fetchmail: fetch mail from a POP, IMAP, ETRN, or ODMR-capable server

Command to display fetchmail manual in Linux: $ man 1 fetchmail

NAME

fetchmail - fetch mail from a POP, IMAP, ETRN, or ODMR-capable server

SYNOPSIS

fetchmail [option...] [mailserver...]
fetchmailconf

DESCRIPTION

fetchmail is a mail-retrieval and forwarding utility; it fetchesmail from remote mailservers and forwards it to your local (client)machine's delivery system. You can then handle the retrieved mail usingnormal mail user agents such as mutt(1), elm(1) orMail(1). The fetchmail utility can be run in a daemon modeto repeatedly poll one or more systems at a specified interval.

The fetchmail program can gather mail from servers supporting anyof the common mail-retrieval protocols: POP2 (legacy, to be removed fromfuture release), POP3, IMAP2bis, IMAP4, and IMAP4rev1. It can also usethe ESMTP ETRN extension and ODMR. (The RFCs describing all theseprotocols are listed at the end of this manual page.)

While fetchmail is primarily intended to be used over on-demandTCP/IP links (such as SLIP or PPP connections), it may also be useful asa message transfer agent for sites which refuse for security reasons topermit (sender-initiated) SMTP transactions with sendmail.

SUPPORT, TROUBLESHOOTING

For troubleshooting, tracing and debugging, you need to increasefetchmail's verbosity to actually see what happens. To do that, pleaserun both of the two following commands,adding all of the options you'd normally use.

env LC_ALL=C fetchmail -V -v --nodetach --nosyslog

(This command line prints in English how fetchmail understands yourconfiguration.)

env LC_ALL=C fetchmail -vvv --nodetach --nosyslog

(This command line actually runs fetchmail with verbose English output.)

Also see

You can omit the LC_ALL=C part above if you want output in the locallanguage (if supported). However if you are posting to mailing lists,please leave it in. The maintainers do not necessarily understand yourlanguage, please use English.

CONCEPTS

If fetchmail is used with a POP or an IMAP server (but not withETRN or ODMR), it has two fundamental modes of operation for each useraccount from which it retrieves mail: singledrop- andmultidrop-mode.

In singledrop-mode,: fetchmail assumes that all messages in the user's account(mailbox) are intended for a single recipient. The identity of therecipient will either default to the local user currently executingfetchmail, or will need to be explicitly specified in theconfiguration file.
: fetchmail uses singledrop-mode when the fetchmailrc configurationcontains at most a single local user specification for a given serveraccount.
In multidrop-mode,: fetchmail assumes that the mail server account actually containsmail intended for any number of different recipients. Therefore,fetchmail must attempt to deduce the proper "envelope recipient"from the mail headers of each message. In this mode of operation,fetchmail almost resembles a mail transfer agent (MTA).
: Note that neither the POP nor IMAP protocols were intended for use inthis fashion, and hence envelope information is often not directlyavailable. The ISP must stores the envelope information in some messageheader and. The ISP must also store one copy of the message perrecipient. If either of the conditions is not fulfilled, this process isunreliable, because fetchmail must then resort to guessing thetrue envelope recipient(s) of a message. This usually fails for mailinglist messages and Bcc:d mail, or mail for multiple recipients in yourdomain.
: fetchmail uses multidrop-mode when more than one local user and/ora wildcard is specified for a particular server account in theconfiguration file.
In ETRN and ODMR modes,: these considerations do not apply, as these protocols are based on SMTP,which provides explicit envelope recipient information. These protocolsalways support multiple recipients.

As each message is retrieved, fetchmail normally delivers it viaSMTP to port 25 on the machine it is running on (localhost), just asthough it were being passed in over a normal TCP/IP link.fetchmail provides the SMTP server with an envelope recipientderived in the manner described previously. The mail will then bedelivered according to your MTA's rules (the Mail Transfer Agent isusually sendmail(8), exim(8), or postfix(8)).Invoking your system's MDA (Mail Delivery Agent) is the duty of yourMTA. All the delivery-control mechanisms (such as .forward files)normally available through your system MTA and local delivery agentswill therefore be applied as usual.

If your fetchmail configuration sets a local MDA (see the --mdaoption), it will be used directly instead of talking SMTP to port 25.

If the program fetchmailconf is available, it will assist you insetting up and editing a fetchmailrc configuration. It runs under the Xwindow system and requires that the language Python and the Tk toolkit(with Python bindings) be present on your system. If you are firstsetting up fetchmail for single-user mode, it is recommended that youuse Novice mode. Expert mode provides complete control of fetchmailconfiguration, including the multidrop features. In either case,the 'Autoprobe' button will tell you the most capable protocol a givenmailserver supports, and warn you of potential problems with thatserver.

GENERAL OPERATION

The behavior of fetchmail is controlled by command-line options and arun control file, ~/.fetchmailrc,the syntax of which we describe in a later section (this file is whatthe fetchmailconf program edits). Command-line options override~/.fetchmailrc declarations.

Each server name that you specify following the options on the commandline will be queried. If you do not specify any servers on the commandline, each 'poll' entry in your ~/.fetchmailrc file will bequeried, unless the idle option is used, which see.

To facilitate the use of fetchmail in scripts and pipelines, itreturns an appropriate exit code upon termination -- see EXIT CODESbelow.

The following options modify the behavior of fetchmail. It isseldom necessary to specify any of these once you have aworking .fetchmailrc file set up.

Almost all options have a corresponding keyword which can be used todeclare them in a .fetchmailrc file.

Some special options are not covered here, but are documented insteadin sections on AUTHENTICATION and DAEMON MODE which follow.

General Options

-? | --help: Displays option help.
-V | --version: Displays the version information for your copy of fetchmail. No mailfetch is performed. Instead, for each server specified, all the optioninformation that would be computed if fetchmail were connecting to thatserver is displayed. Any non-printables in passwords or other string namesare shown as backslashed C-like escape sequences. This option is useful forverifying that your options are set the way you want them.
-c | --check: Return a status code to indicate whether there is mail waiting,without actually fetching or deleting mail (see EXIT CODES below).This option turns off daemon mode (in which it would be useless). Itdoesn't play well with queries to multiple sites, and doesn't workwith ETRN or ODMR. It will return a false positive if you leave read butundeleted mail in your server mailbox and your fetch protocol can'ttell kept messages from new ones. This means it will work with IMAP,not work with POP2, and may occasionally flake out under POP3.
-s | --silent: Silent mode. Suppresses all progress/status messages that arenormally echoed to standard output during a fetch (but does notsuppress actual error messages). The --verbose option overrides this.
-v | --verbose: Verbose mode. All control messages passed between fetchmailand the mailserver are echoed to stdout. Overrides --silent.Doubling this option (-v -v) causes extra diagnostic informationto be printed.
--nosoftbounce: (since v6.3.10, Keyword: set no softbounce, since v6.3.10)
Hard bounce mode. All permanent delivery errors cause messages to bedeleted from the upstream server, see "no softbounce" below.
--softbounce: (since v6.3.10, Keyword: set softbounce, since v6.3.10)
Soft bounce mode. All permanent delivery errors cause messages to beleft on the upstream server if the protocol supports that.This option is on by default to match historic fetchmail documentation,and will be changed to hard bounce mode in the next fetchmail release.

Disposal Options

-a | --all | (since v6.3.3) --fetchall: (Keyword: fetchall, since v3.0)
Retrieve both old (seen) and new messages from the mailserver. Thedefault is to fetch only messages the server has not marked seen.Under POP3, this option also forces the use of RETR rather than TOP.Note that POP2 retrieval behaves as though --all is always on (seeRETRIEVAL FAILURE MODES below) and this option does not work with ETRNor ODMR. While the -a and --all command-line and fetchall rcfileoptions have been supported for a long time, the --fetchallcommand-line option was added in v6.3.3.
-k | --keep: (Keyword: keep)
Keep retrieved messages on the remote mailserver. Normally, messagesare deleted from the folder on the mailserver after they have been retrieved.Specifying the keep option causes retrieved messages to remain inyour folder on the mailserver. This option does not work with ETRN orODMR. If used with POP3, it is recommended to also specify the --uidloption or uidl keyword.
-K | --nokeep: (Keyword: nokeep)
Delete retrieved messages from the remote mailserver. Thisoption forces retrieved mail to be deleted. It may be useful ifyou have specified a default of keep in your.fetchmailrc. This option is forced on with ETRN and ODMR.
-F | --flush: (Keyword: flush)
POP3/IMAP only. This is a dangerous option and can cause mail loss whenused improperly. It deletes old (seen) messages from the mailserverbefore retrieving new messages. Warning: This can cause mail loss ifyou check your mail with other clients than fetchmail, and causefetchmail to delete a message it had never fetched before. It can alsocause mail loss if the mail server marks the message seen afterretrieval (IMAP2 servers). You should probably not use this option in yourconfiguration file. If you use it with POP3, you must use the 'uidl'option. What you probably want is the default setting: if you don'tspecify '-k', then fetchmail will automatically delete messages aftersuccessful delivery.
--limitflush: POP3/IMAP only, since version 6.3.0. Delete oversized messages from themailserver before retrieving new messages. The size limit should beseparately specified with the --limit option. This option does notwork with ETRN or ODMR.

Protocol and Query Options

-p <proto> | --proto <proto> | --protocol <proto>

(Keyword: proto[col])
Specify the protocol to use when communicating with the remotemailserver. If no protocol is specified, the default is AUTO.proto may be one of the following:

AUTO: Tries IMAP, POP3, and POP2 (skipping any of these for which supporthas not been compiled in).
POP2: Post Office Protocol 2 (legacy, to be removed from future release)
POP3: Post Office Protocol 3
APOP: Use POP3 with old-fashioned MD5-challenge authentication.Considered not resistant to man-in-the-middle attacks.
RPOP: Use POP3 with RPOP authentication.
KPOP: Use POP3 with Kerberos V4 authentication on port 1109.
SDPS: Use POP3 with Demon Internet's SDPS extensions.
IMAP: IMAP2bis, IMAP4, or IMAP4rev1 (fetchmail automatically detects their capabilities).
ETRN: Use the ESMTP ETRN option.
ODMR: Use the the On-Demand Mail Relay ESMTP profile.

All these alternatives work in basically the same way (communicatingwith standard server daemons to fetch mail already delivered to amailbox on the server) except ETRN and ODMR. The ETRN modeallows you to ask a compliant ESMTP server (such as BSD sendmail atrelease 8.8.0 or higher) to immediately open a sender-SMTP connectionto your client machine and begin forwarding any items addressed toyour client machine in the server's queue of undelivered mail. TheODMR mode requires an ODMR-capable server and works similarly toETRN, except that it does not require the client machine to havea static DNS.

-U | --uidl: (Keyword: uidl)
Force UIDL use (effective only with POP3). Force client-side trackingof 'newness' of messages (UIDL stands for "unique ID listing" and isdescribed in RFC1939). Use with 'keep' to use a mailbox as a babynews drop for a group of users. The fact that seen messages are skippedis logged, unless error logging is done through syslog while running indaemon mode. Note that fetchmail may automatically enable this optiondepending on upstream server capabilities. Note also that this optionmay be removed and forced enabled in a future fetchmail version. Seealso: --idfile.
--idle (since 6.3.3): (Keyword: idle, since before 6.0.0)
Enable IDLE use (effective only with IMAP). Note that this works withonly one account and one folder at a given time, other folders oraccounts will not be polled when idle is in effect! While the idle rcfilekeyword had been supported for a long time, the --idle command-lineoption was added in version 6.3.3. IDLE use means that fetchmail tellsthe IMAP server to send notice of new messages, so they can be retrievedsooner than would be possible with regular polls.
-P <portnumber> | --service <servicename>: (Keyword: service) Since version 6.3.0.
The service option permits you to specify a service name to connect to.You can specify a decimal port number here, if your services databaselacks the required service-port assignments. See the FAQ item R12 andthe --ssl documentation for details. This replaces the older --portoption.
--port <portnumber>: (Keyword: port)
Obsolete version of --service that does not take service names.Note: this option may be removed from a future version.
--principal <principal>: (Keyword: principal)
The principal option permits you to specify a service principal formutual authentication. This is applicable to POP3 or IMAP with Kerberos4 authentication only. It does not apply to Kerberos 5 or GSSAPI. Thisoption may be removed in a future fetchmail version.
-t <seconds> | --timeout <seconds>: (Keyword: timeout)
The timeout option allows you to set a server-nonresponsetimeout in seconds. If a mailserver does not send a greeting messageor respond to commands for the given number of seconds,fetchmail will drop the connection to it. Without such a timeoutfetchmail might hang until the TCP connection times out, trying to fetchmail from a down host, which may be very long.This would be particularly annoying for a fetchmail running in thebackground. There is a default timeout which fetchmail~-V will report. If agiven connection receives too many timeouts in succession, fetchmail willconsider it wedged and stop retrying. The calling user will be notified byemail if this happens.
: Beginning with fetchmail 6.3.10, the SMTP client uses the recommended minimumtimeouts from RFC-5321 while waiting for the SMTP/LMTP server it is talking to.You can raise the timeouts even more, but you cannot shorten them. This is toavoid a painful situation where fetchmail has been configured with a shorttimeout (a minute or less), ships a long message (many MBytes) to the localMTA, which then takes longer than timeout to respond "OK", which it eventuallywill; that would mean the mail gets delivered properly, but fetchmail cannotnotice it and will thus refetch this big message over and over again.
--plugin <command>: (Keyword: plugin)
The plugin option allows you to use an external program to establish the TCPconnection. This is useful if you want to use ssh, or need some specialfirewalling setup. The program will be looked up in $PATH and can optionallybe passed the hostname and port as arguments using "%h" and "%p" respectively(note that the interpolation logic is rather primitive, and these tokens mustbe bounded by whitespace or beginning of string or end of string).Fetchmail will write to the plugin's stdin and read from the plugin'sstdout.
--plugout <command>: (Keyword: plugout)
Identical to the plugin option above, but this one is used for the SMTPconnections.
-r <name> | --folder <name>: (Keyword: folder[s])
Causes a specified non-default mail folder on the mailserver (orcomma-separated list of folders) to be retrieved. The syntax of thefolder name is server-dependent. This option is not available underPOP3, ETRN, or ODMR.
--tracepolls: (Keyword: tracepolls)
Tell fetchmail to poll trace information in the form 'pollingaccount %s' and 'folder %s' to the Received line it generates,where the %s parts are replaced by the user's remote name, the polllabel, and the folder (mailbox) where available (the Received headeralso normally includes the server's true name). This can be used tofacilitate mail filtering based on the account it is being receivedfrom. The folder information is written only since version 6.3.4.
--ssl: (Keyword: ssl)
Causes the connection to the mail server to be encrypted via SSL, bynegotiating SSL directly after connecting (SSL-wrapped mode).Please see the description of --sslproto below! More information isavailable in the README.SSL file that ships with fetchmail.
: Note that even if this option is omitted, fetchmail may still negotiateSSL in-band for POP3 or IMAP, through the STLS or STARTTLS feature. Youcan use the --sslproto option to modify that behavior.
: If no port is specified, the connection is attempted to the well knownport of the SSL version of the base protocol. This is generally adifferent port than the port used by the base protocol. For IMAP, thisis port 143 for the clear protocol and port 993 for the SSL securedprotocol; for POP3, it is port 110 for the clear text and port 995 forthe encrypted variant.
: If your system lacks the corresponding entries from /etc/services, seethe --service option and specify the numeric port number as given inthe previous paragraph (unless your ISP had directed you to differentports, which is uncommon however).
--sslcert <name>: (Keyword: sslcert)
For certificate-based client authentication. Some SSL encrypted serversrequire client side keys and certificates for authentication. In mostcases, this is optional. This specifies the location of the public keycertificate to be presented to the server at the time the SSL session isestablished. It is not required (but may be provided) if the serverdoes not require it. It may be the same file as the private key(combined key and certificate file) but this is not recommended. Alsosee --sslkey below.
NOTE: If you use client authentication, the user name is fetchedfrom the certificate's CommonName and overrides the name set with--user.
--sslkey <name>: (Keyword: sslkey)
Specifies the file name of the client side private SSL key. Some SSLencrypted servers require client side keys and certificates forauthentication. In most cases, this is optional. This specifiesthe location of the private key used to sign transactions with the serverat the time the SSL session is established. It is not required (but maybe provided) if the server does not require it. It may be the same fileas the public key (combined key and certificate file) but this is notrecommended.
: If a password is required to unlock the key, it will be prompted for atthe time just prior to establishing the session to the server. This cancause some complications in daemon mode.
: Also see --sslcert above.
--sslproto <value>: (Keyword: sslproto, NOTE: semantic changes since v6.4.0)
This option has a dual use, out of historic fetchmail behaviour. Itcontrols both the SSL/TLS protocol version and, if --ssl is notspecified, the STARTTLS behaviour (upgrading the protocol to an SSL orTLS connection in-band). Some other options may however make TLSmandatory.

Only if this option and --ssl are both missing for a poll, there willbe opportunistic TLS for POP3 and IMAP, where fetchmail will attempt toupgrade to TLSv1 or newer.

Recognized values for --sslproto are given below. You should normallychose one of the auto-negotiating options, i. e. 'auto' or one ofthe options ending in a plus (+) character. Note that dependingon OpenSSL library version and configuration, some options causerun-time errors because the requested SSL or TLS versions are notsupported by the particular installed OpenSSL library.

'', the empty string: Disable STARTTLS. If --ssl is given for the same server, log an errorand pretend that 'auto' had been used instead.
'auto': (default). Since v6.4.0. Require TLS. Auto-negotiate TLSv1 or newer, disable SSLv3 downgrade.(fetchmail 6.3.26 and older have auto-negotiated all protocols thattheir OpenSSL library supported, including the broken SSLv3).
'SSL23': see 'auto'.
'SSL3': Require SSLv3 exactly. SSLv3 is broken, not supported on all systems, avoid itif possible. This will make fetchmail negotiate SSLv3 only, and is theonly way besides 'SSL3+' to have fetchmail 6.4.0 or newer permit SSLv3.
'SSL3+': same as 'auto', but permit SSLv3 as well. This is the only waybesides 'SSL3' to have fetchmail 6.4.0 or newer permit SSLv3.
'TLS1': Require TLSv1. This does not negotiate TLSv1.1 or newer, and isdiscouraged. Replace by TLS1+ unless the latter chokes your server.
'TLS1+': Since v6.4.0. See 'auto'.
'TLS1.1': Since v6.4.0. Require TLS v1.1 exactly.
'TLS1.1+': Since v6.4.0. Require TLS. Auto-negotiate TLSv1.1 or newer.
'TLS1.2': Since v6.4.0. Require TLS v1.2 exactly.
'TLS1.2+': Since v6.4.0. Require TLS. Auto-negotiate TLSv1.2 or newer.
Unrecognized parameters: are treated the same as 'auto'.

NOTE: you should hardly ever need to use anything other than '' (toforce an unencrypted connection) or 'auto' (to enforce TLS).

--sslcertck

(Keyword: sslcertck, default enabled since v6.4.0)
--sslcertck causes fetchmail to require that SSL/TLS be used anddisconnect if it can not successfully negotiate SSL or TLS, or if itcannot successfully verify and validate the certificate and follow it toa trust anchor (or trusted root certificate). The trust anchors aregiven as a set of local trusted certificates (see the sslcertfileand sslcertpath options). If the server certificate cannot beobtained or is not signed by one of the trusted ones (directly orindirectly), fetchmail will disconnect, regardless of thesslfingerprint option.

Note that CRL (certificate revocation lists) are only supported inOpenSSL 0.9.7 and newer! Your system clock should also be reasonablyaccurate when using this option.

--nosslcertck

(Keyword: no sslcertck, only in v6.4.X)
The opposite of --sslcertck, this is a disouraged option. It permitsfetchmail to continue connecting even if the server certificate failedthe verification checks. Should only be used together with--sslfingerprint.

--sslcertfile <file>

(Keyword: sslcertfile, since v6.3.17)
Sets the file fetchmail uses to look up local certificates. The default isempty. This can be given in addition to --sslcertpath below, andcertificates specified in --sslcertfile will be processed before thosein --sslcertpath. The option can be used in addition to--sslcertpath.

The file is a text file. It contains the concatenation of trusted CAcertificates in PEM format.

Note that using this option will suppress loading the default SSL trusted CAcertificates file unless you set the environment variableFETCHMAIL_INCLUDE_DEFAULT_X509_CA_CERTS to a non-empty value.

--sslcertpath <directory>

(Keyword: sslcertpath)
Sets the directory fetchmail uses to look up local certificates. The default isyour OpenSSL default directory. The directory must be hashed the way OpenSSLexpects it - every time you add or modify a certificate in the directory, youneed to use the c_rehash tool (which comes with OpenSSL in the tools/subdirectory). Also, after OpenSSL upgrades, you may need to runc_rehash; particularly when upgrading from 0.9.X to 1.0.0.

This can be given in addition to --sslcertfile above, which see forprecedence rules.

Note that using this option will suppress adding the default SSL trusted CAcertificates directory unless you set the environment variableFETCHMAIL_INCLUDE_DEFAULT_X509_CA_CERTS to a non-empty value.

--sslcommonname <common name>

(Keyword: sslcommonname; since v6.3.9)
Use of this option is discouraged. Before using it, contact theadministrator of your upstream server and ask for a proper SSLcertificate to be used. If that cannot be attained, this option can beused to specify the name (CommonName) that fetchmail expects on theserver certificate. A correctly configured server will have this set tothe hostname by which it is reached, and by default fetchmail willexpect as much. Use this option when the CommonName is set to some othervalue, to avoid the "Server CommonName mismatch" warning, and only ifthe upstream server can't be made to use proper certificates.

--sslfingerprint <fingerprint>

(Keyword: sslfingerprint)
Specify the fingerprint of the server key (an MD5 hash of the key) inhexadecimal notation with colons separating groups of two digits. The letterhex digits must be in upper case. This is the formatthat fetchmail uses to report the fingerprint when an SSL connectionis established. When this is specified, fetchmail will compare the server keyfingerprint with the given one, and the connection will fail if they do notmatch, regardless of the sslcertck setting. The connection willalso fail if fetchmail cannot obtain an SSL certificate from the server.This can be used to prevent man-in-the-middle attacks, but the fingerprint from the server must be obtained or verified over a securechannel, and certainly not over the same Internet connection thatfetchmail would use.

Using this option will prevent printing certificate verification errorsas long as --nosslcertck is in effect.

To obtain the fingerprint of a certificate stored in the file cert.pem,try:

 openssl x509 -in cert.pem -noout -md5 -fingerprint

For details, seex509(1ssl).

Delivery Control Options

-S <hosts> | --smtphost <hosts>

(Keyword: smtp[host])
Specify a hunt list of hosts to forward mail to (one or morehostnames, comma-separated). Hosts are tried in list order; the firstone that is up becomes the forwarding target for the current run. Ifthis option is not specified, 'localhost' is used as the default.Each hostname may have a port number following the host name. Theport number is separated from the host name by a slash; the defaultport is "smtp". If you specify an absolute path name (beginning witha /), it will be interpreted as the name of a UNIX socket acceptingLMTP connections (such as is supported by the Cyrus IMAP daemon)Example:

 --smtphost server1,server2/2525,server3,/var/imap/socket/lmtp

This option can be used with ODMR, and will make fetchmail a relaybetween the ODMR server and SMTP or LMTP receiver.

WARNING: if you use address numeric IP addresses here, be sure to use--smtpaddress or --smtpname (either of which see) with a valid SMTPaddress literal!

--fetchdomains <hosts>

(Keyword: fetchdomains)
In ETRN or ODMR mode, this option specifies the list of domains theserver should ship mail for once the connection is turned around. Thedefault is the FQDN of the machine running fetchmail.

-D <domain> | --smtpaddress <domain>

(Keyword: smtpaddress)
Specify the domain to be appended to addresses in RCPT TO lines shippedto SMTP. When this is not specified, the name of the SMTP server (asspecified by --smtphost) is used for SMTP/LMTP and 'localhost' is usedfor UNIX socket/BSMTP.

NOTE: if you intend to use numeric addresses, or so-called addressliterals per the SMTP standard, write them in proper SMTP syntax, forinstance --smtpaddress "[192.0.2.6]" or --smtpaddress"[IPv6:2001:DB8::6]".

--smtpname <user [at] domain>

(Keyword: smtpname)
Specify the domain and user to be put in RCPT TO lines shipped to SMTP.The default user is the current local user. Please also see the NOTEabout --smtpaddress and address literals above.

-Z <nnn> | --antispam <nnn[, nnn]...>

(Keyword: antispam)
Specifies the list of numeric SMTP errors that are to be interpretedas a spam-block response from the listener. A value of -1 disablesthis option. For the command-line option, the list values shouldbe comma-separated. Note that the antispam values only apply to "MAILFROM" responses in the SMTP/LMTP dialogue, but several MTAs (Postfix inits default configuration, qmail) defer the anti-spam response codeuntil after the RCPT TO. --antispam does not work in thesecirc*mstances. Also see --softbounce (default) and its inverse.

-m <command> | --mda <command>

(Keyword: mda)
This option lets fetchmail use a Message or Local Delivery Agent(MDA or LDA) directly, rather than forward via SMTP or LMTP.

To avoid losing mail, use this option only with MDAs like maildrop orMTAs like sendmail that exit with a nonzero status on disk-full and otherdelivery errors; the nonzero status tells fetchmail that delivery failedand prevents the message from being deleted on the server.

If fetchmail is running as root, it sets its user id whiledelivering mail through an MDA as follows: First, the FETCHMAILUSER,LOGNAME, and USER environment variables are checked in this order. Thevalue of the first variable from his list that is defined (even if it isempty!) is looked up in the system user database. If none of thevariables is defined, fetchmail will use the real user id it was startedwith. If one of the variables was defined, but the user stated thereisn't found, fetchmail continues running as root, without checkingremaining variables on the list. Practically, this means that if yourun fetchmail as root (not recommended), it is most useful to define theFETCHMAILUSER environment variable to set the user that the MDA shouldrun as. Some MDAs (such as maildrop) are designed to be setuid root andsetuid to the recipient's user id, so you don't lose functionality thisway even when running fetchmail as unprivileged user. Check the MDA'smanual for details.

Some possible MDAs are "/usr/sbin/sendmail -i -f %F -- %T"(Note:some several older or vendor sendmail versions mistake -- for anaddress, rather than an indicator to mark the end of the option arguments),"/usr/bin/deliver" and "/usr/bin/maildrop -d %T". Local deliveryaddresses will be inserted into the MDA command wherever you place a%T; the mail message's From address will be inserted where you placean %F.

Do NOT enclose the %F or %T string in single quotes!For both %T and %F, fetchmail encloses the addresses in single quotes('), after removing any single quotes they may contain, before the MDAcommand is passed to the shell.

Do NOT use an MDA invocation that dispatches on the contents ofTo/Cc/Bcc, like "sendmail -i -t" or "qmail-inject", it will createmail loops and bring the just wrath of many postmasters down upon yourhead. This is one of the most frequent configuration errors!

Also, do not try to combine multidrop mode with an MDA suchas maildrop that can only accept one address, unless your upstreamstores one copy of the message per recipient and transports the enveloperecipient in a header; you will lose mail.

The well-knownprocmail(1)package is very hard to configure properly, it has a very nasty "fallthrough to the next rule" behavior on delivery errors (even temporaryones, such as out of disk space if another user's mail daemon copies themailbox around to purge old messages), so your mail will end up in thewrong mailbox sooner or later. The proper procmail configuration isoutside the scope of this document. Usingmaildrop(1)is usually much easier, and many users find the filter syntax used bymaildrop easier to understand.

Finally, we strongly advise that you do not use qmail-inject. Thecommand line interface is non-standard without providing benefits fortypical use, and fetchmail makes no attempts to accommodateqmail-inject's deviations from the standard. Some of qmail-inject'scommand-line and environment options are actually dangerous and cancause broken threads, non-detected duplicate messages and forwardingloops.

--lmtp

(Keyword: lmtp)
Cause delivery via LMTP (Local Mail Transfer Protocol). A servicehost and port must be explicitly specified on each host in thesmtphost hunt list (see above) if this option is selected; the defaultport 25 will (in accordance with RFC 2033) not be accepted.

--bsmtp <filename>

(Keyword: bsmtp)
Append fetched mail to a BSMTP file. This simply contains the SMTPcommands that would normally be generated by fetchmail when passingmail to an SMTP listener daemon.

An argument of '-' causes the SMTP batch to be written to standardoutput, which is of limited use: this only makes sense for debugging,because fetchmail's regular output is interspersed on the same channel,so this isn't suitable for mail delivery. This special mode may beremoved in a later release.

Note that fetchmail's reconstruction of MAIL FROM and RCPT TO lines isnot guaranteed correct; the caveats discussed under THE USE AND ABUSE OFMULTIDROP MAILBOXES below apply. This mode has precedence before--mda and SMTP/LMTP.

--bad-header {reject|accept}

(Keyword: bad-header; since v6.3.15)
Specify how fetchmail is supposed to treat messages with bad headers,i. e. headers with bad syntax. Traditionally, fetchmail has rejected suchmessages, but some distributors modified fetchmail to accept them. You can nowconfigure fetchmail's behaviour per server.

Resource Limit Control Options

-l <maxbytes> | --limit <maxbytes>

(Keyword: limit)
Takes a maximum octet size argument, where 0 is thedefault and also the special value designating "no limit".If nonzero, messages larger than this size will not be fetched and willbe left on the server (in foreground sessions, the progress messageswill note that they are "oversized"). If the fetch protocol permits (inparticular, under IMAP or POP3 without the fetchall option) the messagewill not be marked seen.

An explicit --limit of 0 overrides any limits set in yourrun control file. This option is intended for those needing tostrictly control fetch time due to expensive and variable phone rates.

Combined with --limitflush, it can be used to delete oversizedmessages waiting on a server. In daemon mode, oversize notificationsare mailed to the calling user (see the --warnings option). Thisoption does not work with ETRN or ODMR.

-w <interval> | --warnings <interval>

(Keyword: warnings)
Takes an interval in seconds. When you call fetchmailwith a 'limit' option in daemon mode, this controls the interval atwhich warnings about oversized messages are mailed to the calling user(or the user specified by the 'postmaster' option). One suchnotification is always mailed at the end of the the first poll thatthe oversized message is detected. Thereafter, re-notification issuppressed until after the warning interval elapses (it will takeplace at the end of the first following poll).

-b <count> | --batchlimit <count>

(Keyword: batchlimit)
Specify the maximum number of messages that will be shipped to an SMTPlistener before the connection is deliberately torn down and rebuilt(defaults to 0, meaning no limit). An explicit --batchlimit of 0overrides any limits set in your run control file. Whilesendmail(8) normally initiates delivery of a message immediatelyafter receiving the message terminator, some SMTP listeners are not soprompt. MTAs like smail(8) may wait till thedelivery socket is shut down to deliver. This may produce annoyingdelays when fetchmail is processing very large batches. Settingthe batch limit to some nonzero size will prevent these delays. Thisoption does not work with ETRN or ODMR.

-B <number> | --fetchlimit <number>

(Keyword: fetchlimit)
Limit the number of messages accepted from a given server in a singlepoll. By default there is no limit. An explicit --fetchlimit of 0overrides any limits set in your run control file.This option does not work with ETRN or ODMR.

--fetchsizelimit <number>

(Keyword: fetchsizelimit)
Limit the number of sizes of messages accepted from a given server ina single transaction. This option is useful in reducing the delay indownloading the first mail when there are too many mails in themailbox. By default, the limit is 100. If set to 0, sizes of allmessages are downloaded at the start.This option does not work with ETRN or ODMR. For POP3, the only validnon-zero value is 1.

--fastuidl <number>

(Keyword: fastuidl)
Do a binary instead of linear search for the first unseen UID. Binarysearch avoids downloading the UIDs of all mails. This saves time(especially in daemon mode) where downloading the same set of UIDs ineach poll is a waste of bandwidth. The number 'n' indicates how rarelya linear search should be done. In daemon mode, linear search is usedonce followed by binary searches in 'n-1' polls if 'n' is greater than1; binary search is always used if 'n' is 1; linear search is alwaysused if 'n' is 0. In non-daemon mode, binary search is used if 'n' is1; otherwise linear search is used. The default value of 'n' is 4.This option works with POP3 only.

-e <count> | --expunge <count>

(Keyword: expunge)
Arrange for deletions to be made final after a given number ofmessages. Under POP2 or POP3, fetchmail cannot make deletions finalwithout sending QUIT and ending the session -- with this option on,fetchmail will break a long mail retrieval session into multiplesub-sessions, sending QUIT after each sub-session. This is a gooddefense against line drops on POP3 servers. Under IMAP,fetchmail normally issues an EXPUNGE command after each deletionin order to force the deletion to be done immediately. This is safestwhen your connection to the server is flaky and expensive, as it avoidsresending duplicate mail after a line hit. However, on largemailboxes the overhead of re-indexing after every message can slam theserver pretty hard, so if your connection is reliable it is good to doexpunges less frequently. Also note that some servers enforce a delayof a few seconds after each quit, so fetchmail may not be able to getback in immediately after an expunge -- you may see "lock busy" errorsif this happens. If you specify this option to an integer N,it tells fetchmail to only issue expunges on every Nth delete. Anargument of zero suppresses expunges entirely (so no expunges at allwill be done until the end of run). This option does not work with ETRNor ODMR.

Authentication Options

-u <name> | --user <name> | --username <name>

(Keyword: user[name])
Specifies the user identification to be used when logging in to the mailserver.The appropriate user identification is both server and user-dependent.The default is your login name on the client machine that is runningfetchmail.See USER AUTHENTICATION below for a complete description.

-I <specification> | --interface <specification>

(Keyword: interface)
Require that a specific interface device be up and have a specific localor remote IPv4 (IPv6 is not supported by this option yet) address (orrange) before polling. Frequently fetchmailis used over a transient point-to-point TCP/IP link established directlyto a mailserver via SLIP or PPP. That is a relatively secure channel.But when other TCP/IP routes to the mailserver exist (e.g. when the linkis connected to an alternate ISP), your username and password may bevulnerable to snooping (especially when daemon mode automatically pollsfor mail, shipping a clear password over the net at predictableintervals). The --interface option may be used to prevent this. Whenthe specified link is not up or is not connected to a matching IPaddress, polling will be skipped. The format is:

 interface/iii.iii.iii.iii[/mmm.mmm.mmm.mmm]

The field before the first slash is the interface name (i.e. sl0, ppp0etc.). The field before the second slash is the acceptable IP address.The field after the second slash is a mask which specifies a range ofIP addresses to accept. If no mask is present 255.255.255.255 isassumed (i.e. an exact match). This option is currently only supportedunder Linux and FreeBSD. Please see the monitor section for belowfor FreeBSD specific information.

Note that this option may be removed from a future fetchmail version.

-M <interface> | --monitor <interface>

(Keyword: monitor)
Daemon mode can cause transient links which are automatically taken downafter a period of inactivity (e.g. PPP links) to remain upindefinitely. This option identifies a system TCP/IP interface to bemonitored for activity. After each poll interval, if the link is up butno other activity has occurred on the link, then the poll will beskipped. However, when fetchmail is woken up by a signal, themonitor check is skipped and the poll goes through unconditionally.This option is currently only supported under Linux and FreeBSD.For the monitor and interface options to work for non rootusers under FreeBSD, the fetchmail binary must be installed SGID kmem.This would be a security hole, but fetchmail runs with the effective GIDset to that of the kmem group only when interface data is beingcollected.

Note that this option may be removed from a future fetchmail version.

--auth <type>

(Keyword: auth[enticate])
This option permits you to specify an authentication type (see USERAUTHENTICATION below for details). The possible values are any,password, kerberos_v5, kerberos (or, forexcruciating exactness, kerberos_v4), gssapi,cram-md5, otp, ntlm, msn (only for POP3),external (only IMAP) and ssh.When any (the default) is specified, fetchmail triesfirst methods that don't require a password (EXTERNAL, GSSAPI, KERBEROS IV,KERBEROS 5); then it looks for methods that mask your password(CRAM-MD5, NTLM, X-OTP - note that MSN is only supported for POP3, but notautoprobed); and only if the server doesn'tsupport any of those will it ship your password en clair. Other valuesmay be used to force various authentication methods(ssh suppresses authentication and is thus useful for IMAP PREAUTH).(external suppresses authentication and is thus useful for IMAP EXTERNAL).Any value other than password, cram-md5, ntlm,msn or otp suppresses fetchmail's normal inquiry for apassword. Specify ssh when you are using an end-to-end secureconnection such as an ssh tunnel; specify external when you useTLS with client authentication and specify gssapi orkerberos_v4 if you are using a protocol variant that employsGSSAPI or K4. Choosing KPOP protocol automatically selects Kerberosauthentication. This option does not work with ETRN. GSSAPI service names arein line with RFC-2743 and IANA registrations, see

Miscellaneous Options

-f <pathname> | --fetchmailrc <pathname>

Specify a non-default name for the ~/.fetchmailrcrun control file. The pathname argument must be either "-" (a singledash, meaning to read the configuration from standard input) or afilename. Unless the --version option is also on, a named fileargument must have permissions no more open than 0700 (u=rwx,g=,o=) orelse be /dev/null.

-i <pathname> | --idfile <pathname>

(Keyword: idfile)
Specify an alternate name for the .fetchids file used to save messageUIDs. NOTE: since fetchmail 6.3.0, write access to the directorycontaining the idfile is required, as fetchmail writes a temporary fileand renames it into the place of the real idfile only if the temporaryfile has been written successfully. This avoids the truncation ofidfiles when running out of disk space.

--pidfile <pathname>

(Keyword: pidfile; since fetchmail v6.3.4)
Override the default location of the PID file. Default: see"ENVIRONMENT" below.

-n | --norewrite

(Keyword: no rewrite)
Normally, fetchmail edits RFC-822 address headers (To, From, Cc,Bcc, and Reply-To) in fetched mail so that any mail IDs local to theserver are expanded to full addresses (@ and the mailserver hostname areappended). This enables replies on the client to get addressedcorrectly (otherwise your mailer might think they should be addressed tolocal users on the client machine!). This option disables the rewrite.(This option is provided to pacify people who are paranoid about havingan MTA edit mail headers and want to know they can prevent it, but it isgenerally not a good idea to actually turn off rewrite.)When using ETRN or ODMR, the rewrite option is ineffective.

-E <line> | --envelope <line>

(Keyword: envelope; Multidrop only)
In the configuration file, an enhanced syntax is used:
envelope [<count>] <line>

This option changes the header fetchmail assumes will carry a copyof the mail's envelope address. Normally this is 'X-Envelope-To'.Other typically found headers to carry envelope information are'X-Original-To' and 'Delivered-To'. Now, since these headers arenot standardized, practice varies. See the discussion of multidropaddress handling below. As a special case, 'envelope "Received"'enables parsing of sendmail-style Received lines. This is the default,but discouraged because it is not fully reliable.

Note that fetchmail expects the Received-line to be in a specificformat: It must contain "by host for address", wherehost must match one of the mailserver names that fetchmailrecognizes for the account in question.

The optional count argument (only available in the configuration file)determines how many header lines of this kind are skipped. A count of 1means: skip the first, take the second. A count of 2 means: skip thefirst and second, take the third, and so on.

-Q <prefix> | --qvirtual <prefix>

(Keyword: qvirtual; Multidrop only)
The string prefix assigned to this option will be removed from the username found in the header specified with the envelope option(before doing multidrop name mapping or localdomain checking,if either is applicable). This option is useful if you are usingfetchmail to collect the mail for an entire domain and your ISP(or your mail redirection provider) is using qmail.One of the basic features of qmail is the Delivered-To:message header. Whenever qmail delivers a message to a local mailboxit puts the username and hostname of the envelope recipient on thisline. The major reason for this is to prevent mail loops. To set upqmail to batch mail for a disconnected site the ISP-mailhost will havenormally put that site in its 'Virtualhosts' control file so it willadd a prefix to all mail addresses for this site. This results in mailsent to 'username [at] userhost.userdom.dom.com' having aDelivered-To: line of the form:

Delivered-To: mbox-userstr-username [at] userhost.example.com

The ISP can make the 'mbox-userstr-' prefix anything they choosebut a string matching the user host name is likely.By using the option 'envelope Delivered-To:' you can make fetchmail reliablyidentify the original envelope recipient, but you have to strip the'mbox-userstr-' prefix to deliver to the correct user.This is what this option is for.

--configdump

Parse the ~/.fetchmailrc file, interpret any command-line optionsspecified, and dump a configuration report to standard output. Theconfiguration report is a data structure assignment in the languagePython. This option is meant to be used with an interactive~/.fetchmailrc editor like fetchmailconf, written in Python.

-y | --yydebug

Enables parser debugging, this option is meant to be used by developersonly.

Removed Options

-T | --netsec: Removed before version 6.3.0, the required underlying inet6_apps libraryhad been discontinued and is no longer available.

USER AUTHENTICATION AND ENCRYPTION

All modes except ETRN require authentication of the client to the server.Normal user authentication in fetchmail is very much like theauthentication mechanism offtp(1).The correct user-id and password depend upon the underlying securitysystem at the mailserver.

If the mailserver is a Unix machine on which you have an ordinary useraccount, your regular login name and password are used withfetchmail.If you use the same login name on both the server and the client machines,you needn't worry about specifying a user-id with the-uoption -- the default behavior is to use your login name on theclient machine as the user-id on the server machine. If you use adifferent login name on the server machine, specify that login namewith the-uoption. e.g. if your login name is 'jsmith' on a machine named 'mailgrunt',you would start fetchmail as follows:

: fetchmail -u jsmith mailgrunt

The default behavior of fetchmail is to prompt you for yourmailserver password before the connection is established. This is thesafest way to use fetchmail and ensures that your password willnot be compromised. You may also specify your password in your~/.fetchmailrc file. This is convenient when usingfetchmail in daemon mode or with scripts.

Using netrc files

If you do not specify a password, and fetchmail cannot extract onefrom your ~/.fetchmailrc file, it will look for a ~/.netrcfile in your home directory before requesting one interactively; if anentry matching the mailserver is found in that file, the password willbe used. Fetchmail first looks for a match on poll name; if it finds none,it checks for a match on via name. See theftp(1)man page for details of the syntax of the ~/.netrcfile. To show a practical example, a .netrc might look likethis:

machine hermes.example.orglogin joepassword topsecret

You can repeat this block with different user information if you need toprovide more than one password.

This feature may allow you to avoid duplicating passwordinformation in more than one file.

On mailservers that do not provide ordinary user accounts, your user-id andpassword are usually assigned by the server administrator when you apply fora mailbox on the server. Contact your server administrator if you don't knowthe correct user-id and password for your mailbox account.

POP3 VARIANTS

Early versions of POP3 (RFC1081, RFC1225) supported a crude form ofindependent authentication using the .rhosts file on themailserver side. Under this RPOP variant, a fixed per-user IDequivalent to a password was sent in clear over a link to a reservedport, with the command RPOP rather than PASS to alert the server that itshould do special checking. RPOP is supported by fetchmail(you can specify 'protocol RPOP' to have the program send 'RPOP'rather than 'PASS') but its use is strongly discouraged, and supportwill be removed from a future fetchmail version. Thisfacility was vulnerable to spoofing and was withdrawn in RFC1460.

RFC1460 introduced APOP authentication. In this variant of POP3,you register an APOP password on your server host (on some servers, theprogram to do this is called popauth(8)). You put the samepassword in your ~/.fetchmailrc file. Each time fetchmaillogs in, it sends an MD5 hash of your password and the server greetingtime to the server, which can verify it by checking its authorizationdatabase.

Note that APOP is no longer considered resistant againstman-in-the-middle attacks.

RETR or TOP

fetchmail makes some efforts to make the server believe messageshad not been retrieved, by using the TOP command with a large number oflines when possible. TOP is a command that retrieves the full headerand a fetchmail-specified amount of body lines. It is optional andtherefore not implemented by all servers, and some are known toimplement it improperly. On many servers however, the RETR command whichretrieves the full message with header and body, sets the "seen" flag(for instance, in a web interface), whereas the TOP command does not dothat.

fetchmail will always use the RETR command if "fetchall" is set.fetchmail will also use the RETR command if "keep" is set and"uidl" is unset. Finally, fetchmail will use the RETR command onMaillennium POP3/PROXY servers (used by Comcast) to avoid a deliberateTOP misinterpretation in this server that causes message corruption.

In all other cases, fetchmail will use the TOP command. Thisimplies that in "keep" setups, "uidl" must be set if "TOP" is desired.

Note that this description is true for the current version offetchmail, but the behavior may change in future versions. Inparticular, fetchmail may prefer the RETR command because the TOPcommand causes much grief on some servers and is only optional.

ALTERNATE AUTHENTICATION FORMS

If your fetchmail was built with Kerberos support and you specifyKerberos authentication (either with --auth or the .fetchmailrcoption authenticate kerberos_v4) it will try to get a Kerberosticket from the mailserver at the start of each query. Note: ifeither the pollname or via name is 'hesiod', fetchmail will try to useHesiod to look up the mailserver.

If you use POP3 or IMAP with GSSAPI authentication, fetchmail willexpect the server to have RFC1731- or RFC1734-conforming GSSAPIcapability, and will use it. Currently this has only been tested overKerberos V, so you're expected to already have a ticket-grantingticket. You may pass a username different from your principal nameusing the standard --user command or by the .fetchmailrcoption user.

If your IMAP daemon returns the PREAUTH response in its greeting line,fetchmail will notice this and skip the normal authentication step.This can be useful, e.g. if you start imapd explicitly using ssh.In this case you can declare the authentication value 'ssh' on thatsite entry to stop .fetchmail from asking you for a passwordwhen it starts up.

If you use client authentication with TLS1 and your IMAP daemonreturns the AUTH=EXTERNAL response, fetchmail will notice thisand will use the authentication shortcut and will not send thepassphrase. In this case you can declare the authentication value 'external'
on that site to stopfetchmailfrom asking you for a passwordwhen it starts up.

Secure Socket Layers (SSL) and Transport Layer Security (TLS)

All retrieval protocols can use SSL or TLS wrapping for thetransport. Additionally, POP3 and IMAP retrival can also negotiateSSL/TLS by means of STARTTLS (or STLS).

Note that fetchmail currently uses the OpenSSL library, which isseverely underdocumented, so failures may occur just because theprogrammers are not aware of OpenSSL's requirement of the day.For instance, since v6.3.16, fetchmail callsOpenSSL_add_all_algorithms(), which is necessary to support certificatesusing SHA256 on OpenSSL 0.9.8 -- this information is deeply hidden inthe documentation and not at all obvious. Please do not hesitate toreport subtle SSL failures.

You can access SSL encrypted services by specifying the options startingwith --ssl, such as --ssl, --sslproto, --sslcertck, and others.You can also do this using the corresponding user options in the .fetchmailrcfile. Some services, such as POP3 and IMAP, havedifferent well known ports defined for the SSL encrypted services. Theencrypted ports will be selected automatically when SSL is enabled andno explicit port is specified. Also, the --sslcertck command line orsslcertck run control file option should be used to force strictcertificate checking with older fetchmail versions - see below.

If SSL is not configured, fetchmail will usually opportunistically try to useSTARTTLS. STARTTLS can be enforced by using --sslproto~auto anddefeated by using --sslproto~''.TLS connections use the same port as the unencrypted version of theprotocol and negotiate TLS via special command. The --sslcertckcommand line or sslcertck run control file option should be used toforce strict certificate checking - see below.

--sslcertck is recommended:When connecting to an SSL or TLS encrypted server, theserver presents a certificate to the client for validation. Thecertificate is checked to verify that the common name in the certificatematches the name of the server being contacted and that the effectiveand expiration dates in the certificate indicate that it is currentlyvalid. If any of these checks fail, a warning message is printed, butthe connection continues. The server certificate does not need to besigned by any specific Certifying Authority and may be a "self-signed"certificate. If the --sslcertck command line option or sslcertck runcontrol file option is used, fetchmail will instead abort if any ofthese checks fail, because it must assume that there is aman-in-the-middle attack in this scenario, hence fetchmail must notexpose cleartext passwords. Use of the sslcertck or --sslcertck optionis therefore advised; it has become the default in fetchmail 6.4.0.

Some SSL encrypted servers may request a client side certificate. A clientside public SSL certificate and private SSL key may be specified. Ifrequested by the server, the client certificate is sent to the server forvalidation. Some servers may require a valid client certificate and mayrefuse connections if a certificate is not provided or if the certificateis not valid. Some servers may require client side certificates be signedby a recognized Certifying Authority. The format for the key files andthe certificate files is that required by the underlying SSL libraries(OpenSSL in the general case).

A word of care about the use of SSL: While above mentionedsetup with self-signed server certificates retrieved over the wirescan protect you from a passive eavesdropper, it doesn't help against anactive attacker. It's clearly an improvement over sending thepasswords in clear, but you should be aware that a man-in-the-middleattack is trivially possible (in particular with tools such as). Use of strict certificate checking with a certification authorityrecognized by server and client, or perhaps of an SSH tunnel (see belowfor some examples) is preferable if you care seriously about thesecurity of your mailbox and passwords.

ESMTP AUTH

fetchmail also supports authentication to the ESMTP server on theclient side according to RFC 2554. You can specify a name/password pairto be used with the keywords 'esmtpname' and 'esmtppassword'; the formerdefaults to the username of the calling user.

DAEMON MODE

Introducing the daemon mode

In daemon mode, fetchmail puts itself into the background and runsforever, querying each specified host and then sleeping for a givenpolling interval.

Starting the daemon mode

There are several ways to make fetchmail work in daemon mode. On thecommand line, --daemon<interval> or -d<interval>option runs fetchmail in daemon mode. You must specify a numericargument which is a polling interval (time to wait after completing awhole poll cycle with the last server and before starting the next pollcycle with the first server) in seconds.

Example: simply invoking

: fetchmail -d 900

will, therefore, poll all the hosts described in your ~/.fetchmailrcfile (except those explicitly excluded with the 'skip' verb) a bit lessoften than once every 15 minutes (exactly: 15 minutes + time that thepoll takes).

It is also possible to set a polling intervalin your ~/.fetchmailrc file by saying 'set daemon<interval>',where <interval> is an integer number of seconds. If you do this,fetchmail will always start in daemon mode unless you override it withthe command-line option --daemon 0 or -d0.

Only one daemon process is permitted per user; in daemon mode,fetchmail sets up a per-user lockfile to guarantee this.(You can however cheat and set the FETCHMAILHOME environment variable toovercome this setting, but in that case, it is your responsibility tomake sure you aren't polling the same server with two processes at thesame time.)

Awakening the background daemon

Normally, calling fetchmail with a daemon in the background sends awake-up signal to the daemon and quits without output. The backgrounddaemon then starts its next poll cycle immediately. The wake-up signal,SIGUSR1, can also be sent manually. The wake-up action also clears any'wedged' flags indicating that connections have wedged due to failedauthentication or multiple timeouts.

Terminating the background daemon

The option-qor--quitwill kill a running daemon process instead of waking it up (if thereis no such process, fetchmail will notify you).If the --quit option appears last on the command line, fetchmailwill kill the running daemon process and then quit. Otherwise,fetchmail will first kill a running daemon process and thencontinue running with the other options.

Useful options for daemon mode

The-L <filename>or--logfile <filename>option (keyword: set logfile) is only effective when fetchmail isdetached and in daemon mode. Note that the logfile must existbefore fetchmail is run, you can use thetouch(1)command with the filename as its sole argument to create it.
This option allows you to redirect status messagesinto a specified logfile (follow the option with the logfile name). Thelogfile is opened for append, so previous messages aren't deleted. Thisis primarily useful for debugging configurations. Note that fetchmaildoes not detect if the logfile is rotated, the logfile is only openedonce when fetchmail starts. You need to restart fetchmail after rotatingthe logfile and before compressing it (if applicable).

The--syslogoption (keyword: set syslog) allows you to redirect status and errormessages emitted to thesyslog(3)system daemon if available.Messages are logged with an id of fetchmail, the facility LOG_MAIL,and priorities LOG_ERR, LOG_ALERT or LOG_INFO.This option is intended for logging status and error messages whichindicate the status of the daemon and the results while fetching mailfrom the server(s).Error messages for command line options and parsing the .fetchmailrcfile are still written to stderr, or to the specified log file.The--nosyslogoption turns off use ofsyslog(3),assuming it's turned on in the ~/.fetchmailrc file.This option is overridden, in certain situations, by --logfile (whichsee).

The-Nor--nodetachoption suppresses backgrounding and detachment of the daemon processfrom its control terminal. This is useful for debugging or whenfetchmail runs as the child of a supervisor process such asinit(8)or Gerrit Pape'srunit(8).Note that this also causes the logfile option to be ignored.

Note that while running in daemon mode polling a POP2 or IMAP2bis server,transient errors (such as DNS failures or sendmail delivery refusals)may force the fetchall option on for the duration of the next pollingcycle. This is a robustness feature. It means that if a message isfetched (and thus marked seen by the mailserver) but not deliveredlocally due to some transient error, it will be re-fetched during thenext poll cycle. (The IMAP logic doesn't delete messages untilthey're delivered, so this problem does not arise.)

If you touch or change the ~/.fetchmailrc file while fetchmail isrunning in daemon mode, this will be detected at the beginning of thenext poll cycle. When a changed ~/.fetchmailrc is detected,fetchmail rereads it and restarts from scratch (using exec(2); no stateinformation is retained in the new instance). Note that if fetchmailneeds to query for passwords, of that if you break the~/.fetchmailrc file's syntax, the new instance will softly andsilently vanish away on startup.

ADMINISTRATIVE OPTIONS

The--postmaster <name>option (keyword: set postmaster) specifies the last-resort username towhich multidrop mail is to be forwarded if no matching local recipientcan be found. It is also used as destination of undeliverable mail ifthe 'bouncemail' global option is off and additionally for spam-blockedmail if the 'bouncemail' global option is off and the 'spambounce'global option is on. This option defaults to the user who invokedfetchmail.If the invoking user is root, then the default of this option isthe user 'postmaster'. Setting postmaster to the empty string causessuch mail as described above to be discarded - this however is usually abad idea.See also the description of the 'FETCHMAILUSER' environment variable inthe ENVIRONMENT section below.

The--nobouncebehaves like the "set no bouncemail" global option, which see.

The--invisibleoption (keyword: set invisible) tries to make fetchmail invisible.Normally, fetchmail behaves like any other MTA would -- it generates aReceived header into each message describing its place in the chain oftransmission, and tells the MTA it forwards to that the mail came fromthe machine fetchmail itself is running on. If the invisible optionis on, the Received header is suppressed and fetchmail tries to spoofthe MTA it forwards to into thinking it came directly from themailserver host.

The--showdotsoption (keyword: set showdots) forces fetchmail to show progress dotseven if the output goes to a file or fetchmail is not in verbose mode.Fetchmail shows the dots by default when run in --verbose modeand output goes to console. This option is ignored in --silent mode.

By specifying the--tracepollsoption, you can ask fetchmail to add information to the Receivedheader on the form "polling {label} account {user}", where {label} isthe account label (from the specified rcfile, normally ~/.fetchmailrc)and {user} is the username which is used to log on to the mailserver. This header can be used to make filtering email where nouseful header information is available and you want mail fromdifferent accounts sorted into different mailboxes (this could, forexample, occur if you have an account on the same server running amailing list, and are subscribed to the list using that account). Thedefault is not adding any such header. In.fetchmailrc,this is called 'tracepolls'.

RETRIEVAL FAILURE MODES

The protocols fetchmail uses to talk to mailservers are next tobulletproof. In normal operation forwarding to port 25, no message isever deleted (or even marked for deletion) on the host until the SMTPlistener on the client side has acknowledged to fetchmail thatthe message has been either accepted for delivery or rejected due to aspam block.

When forwarding to an MDA, however, there is more possibilityof error. Some MDAs are 'safe' and reliably return a nonzero statuson any delivery error, even one due to temporary resource limits.Themaildrop(1)program is like this; so are most programs designed as mail transportagents, such assendmail(1),including the sendmail wrapper of Postfix andexim(1).These programs give back a reliable positive acknowledgement andcan be used with the mda option with no risk of mail loss. UnsafeMDAs, though, may return 0 even on delivery failure. If thishappens, you will lose mail.

The normal mode of fetchmail is to try to download only 'new'messages, leaving untouched (and undeleted) messages you have alreadyread directly on the server (or fetched with a previous fetchmail--keep). But you may find that messages you've already read on theserver are being fetched (and deleted) even when you don't specify--all. There are several reasons this can happen.

One could be that you're using POP2. The POP2 protocol includes norepresentation of 'new' or 'old' state in messages, so fetchmailmust treat all messages as new all the time. But POP2 is obsolete, sothis is unlikely.

A potential POP3 problem might be servers that insert messagesin the middle of mailboxes (some VMS implementations of mail arerumored to do this). The fetchmail code assumes that newmessages are appended to the end of the mailbox; when this is not trueit may treat some old messages as new and vice versa. Using UIDL whilstsetting fastuidl 0 might fix this, otherwise, consider switching to IMAP.

Yet another POP3 problem is that if they can't make tempfiles in theuser's home directory, some POP3 servers will hand back anundocumented response that causes fetchmail to spuriously report "Nomail".

The IMAP code uses the presence or absence of the server flag \Seento decide whether or not a message is new. This isn't the right thingto do, fetchmail should check the UIDVALIDITY and use UID, but itdoesn't do that yet. Under Unix, it counts on your IMAP server to noticethe BSD-style Status flags set by mail user agents and set the \Seenflag from them when appropriate. All Unix IMAP servers we know of dothis, though it's not specified by the IMAP RFCs. If you ever trip overa server that doesn't, the symptom will be that messages you havealready read on your host will look new to the server. In this(unlikely) case, only messages you fetched with fetchmail --keepwill be both undeleted and marked old.

In ETRN and ODMR modes, fetchmail does not actually retrieve messages;instead, it asks the server's SMTP listener to start a queue flushto the client via SMTP. Therefore it sends only undelivered messages.

SPAM FILTERING

Many SMTP listeners allow administrators to set up 'spam filters' thatblock unsolicited email from specified domains. A MAIL FROM or DATA line thattriggers this feature will elicit an SMTP response which(unfortunately) varies according to the listener.

Newer versions ofsendmailreturn an error code of 571.

According to RFC2821, the correct thing to return in this situation is550 "Requested action not taken: mailbox unavailable" (the draft adds"[E.g., mailbox not found, no access, or command rejected for policyreasons].").

Older versions of theeximMTA return 501 "Syntax error in parameters or arguments".

ThepostfixMTA runs 554 as an antispam response.

Zmailermay reject code with a 500 response (followed by an enhanced statuscode that contains more information).

Return codes whichfetchmailtreats as antispam responses and discardsthe message can be set with the 'antispam' option. This is one of theonlythree circ*mstance under which fetchmail ever discards mail (the othersare the 552 and 553 errors described below, and the suppression ofmultidropped messages with a message-ID already seen).

Iffetchmailis fetching from an IMAP server, the antispam response will be detected andthe message rejected immediately after the headers have been fetched,without reading the message body. Thus, you won't pay for downloadingspam message bodies.

By default, the list of antispam responses is empty.

If the spambounce global option is on, mail that is spam-blockedtriggers an RFC1892/RFC1894 bounce message informing the originator thatwe do not accept mail from it. See also BUGS.

SMTP/ESMTP ERROR HANDLING

Besides the spam-blocking described above, fetchmail takes specialactions --- that may be modified by the --softbounce option --- onthe following SMTP/ESMTP error response codes

452 (insufficient system storage): Leave the message in the server mailbox for later retrieval.
552 (message exceeds fixed maximum message size): Delete the message from the server. Send bounce-mail to theoriginator.
553 (invalid sending domain): Delete the message from the server. Don't even try to sendbounce-mail to the originator.

Other errors greater or equal to 500 trigger bounce mail back to theoriginator, unless suppressed by --softbounce. See also BUGS.

THE RUN CONTROL FILE

The preferred way to set up fetchmail is to write a.fetchmailrc file in your home directory (you may do thisdirectly, with a text editor, or indirectly via fetchmailconf).When there is a conflict between the command-line arguments and thearguments in this file, the command-line arguments take precedence.

To protect the security of your passwords,your ~/.fetchmailrc may not normally have more than 0700 (u=rwx,g=,o=) permissions;fetchmailwill complain and exit otherwise (this check is suppressed when--version is on).

You may read the .fetchmailrc file as a list of commands tobe executed whenfetchmailis called with no arguments.

Run Control Syntax

Comments begin with a '#' and extend through the end of the line.Otherwise the file consists of a series of server entries or globaloption statements in a free-format, token-oriented syntax.

There are four kinds of tokens: grammar keywords, numbers(i.e. decimal digit sequences), unquoted strings, and quoted strings.A quoted string is bounded by double quotes and may containwhitespace (and quoted digits are treated as a string). Note thatquoted strings will also contain line feed characters if they run acrosstwo or more lines, unless you use a backslash to join lines (see below).An unquoted string is any whitespace-delimited token that is neithernumeric, string quoted nor contains the special characters ',', ';',':', or '='.

Any amount of whitespace separates tokens in server entries, but isotherwise ignored. You may use backslash escape sequences (\n for LF,\t for HT, \b for BS, \r for CR, \nnn for decimal (wherennn cannot start with a 0), \0ooo for octal, and \xhh forhex) to embed non-printable characters or string delimiters in strings.In quoted strings, a backslash at the very end of a line will cause thebackslash itself and the line feed (LF or NL, new line) character to beignored, so that you can wrap long strings. Without the backslash at theline end, the line feed character would become part of the string.

Warning:while these resemble C-style escape sequences, they are not the same.fetchmail only supports these eight styles. C supports more escapesequences that consist of backslash (\) and a single character, butdoes not support decimal codes and does not require the leading 0 inoctal notation. Example: fetchmail interprets \233 the same as \xE9(Latin small letter e with acute), where C would interpret \233 asoctal 0233 = \x9B (CSI, control sequence introducer).

Each server entry consists of one of the keywords 'poll' or 'skip',followed by a server name, followed by server options, followed by anynumber of user (or username) descriptions, followed by user options.Note: the most common cause of syntax errors is mixing up user andserver options or putting user options before the user descriptions.

For backward compatibility, the word 'server' is a synonym for 'poll'.

You can use the noise keywords 'and', 'with','has', 'wants', and 'options' anywhere in an entry to makeit resemble English. They're ignored, but but can make entries mucheasier to read at a glance. The punctuation characters ':', ';' and',' are also ignored.

Poll vs. Skip

The 'poll' verb tells fetchmail to query this host when it is run withno arguments. The 'skip' verb tellsfetchmailnot to poll this host unless it is explicitly named on the commandline. (The 'skip' verb allows you to experiment with test entriessafely, or easily disable entries for hosts that are temporarily down.)

Keyword/Option Summary

Here are the legal options. Keyword suffixes enclosed insquare brackets are optional. Those corresponding to short command-lineoptions are followed by '-' and the appropriate option letter. Ifoption is only relevant to a single mode of operation, it is noted as's' or 'm' for singledrop- or multidrop-mode, respectively.

Keywords Not Corresponding To Option Switches

The 'folder' and 'smtphost' options (unlike their command-lineequivalents) can take a space- or comma-separated list of namesfollowing them.

All options correspond to the obvious command-line arguments, exceptthe following: 'via', 'interval', 'aka', 'is', 'to', 'dns'/'no dns','checkalias'/'no checkalias', 'password', 'preconnect', 'postconnect','localdomains', 'stripcr'/'no stripcr', 'forcecr'/'no forcecr','pass8bits'/'no pass8bits' 'dropstatus/no dropstatus','dropdelivered/no dropdelivered', 'mimedecode/no mimedecode', 'no idle',and 'no envelope'.

The 'via' option is for if you want to have morethan one configuration pointing at the same site. If it is present,the string argument will be taken as the actual DNS name of themailserver host to query.This will override the argument of poll, which can then simply be adistinct label for the configuration (e.g. what you would give on thecommand line to explicitly query this host).

The 'interval' option (which takes a numeric argument) allows you to poll aserver less frequently than the basic poll interval. If you say'interval N' the server this option is attached to will only bequeried every N poll intervals.

Singledrop vs. Multidrop options

Please ensure you read the section titledTHE USE AND ABUSE OF MULTIDROP MAILBOXES if you intend to use multidrop mode.

The 'is' or 'to' keywords associate the following local (client)name(s) (or server-name to client-name mappings separated by =) withthe mailserver user name in the entry. If an is/to list has '*' asits last name, unrecognized names are simply passed through. Note thatuntil fetchmail version 6.3.4 inclusively, these lists could onlycontain local parts of user names (fetchmail would only look at the partbefore the @ sign). fetchmail versions 6.3.5 andnewer support full addresses on the left hand side of these mappings,and they take precedence over any 'localdomains', 'aka', 'via' orsimilar mappings.

A single local name can be used to support redirecting your mail whenyour username on the client machine is different from your name on themailserver. When there is only a single local name, mail is forwardedto that local username regardless of the message's Received, To, Cc,and Bcc headers. In this case,fetchmailnever does DNS lookups.

When there is more than one local name (or name mapping),fetchmail looks at the envelope header, if configured, andotherwise at the Received, To, Cc, and Bcc headers of retrieved mail(this is 'multidrop mode'). It looks for addresses with hostname partsthat match your poll name or your 'via', 'aka' or 'localdomains'options, and usually also for hostname parts which DNS tells it arealiases of the mailserver. See the discussion of 'dns', 'checkalias','localdomains', and 'aka' for details on how matching addresses arehandled.

If fetchmail cannot match any mailserver usernames orlocaldomain addresses, the mail will be bounced.Normally it will be bounced to the sender, but if the 'bouncemail'global option is off, the mail will go to the local postmaster instead.(see the 'postmaster' global option). See also BUGS.

The 'dns' option (normally on) controls the way addresses frommultidrop mailboxes are checked. On, it enables logic to check eachhost address that does not match an 'aka' or 'localdomains' declarationby looking it up with DNS. When a mailserver username is recognizedattached to a matching hostname part, its local mapping is added tothe list of local recipients.

The 'checkalias' option (normally off) extends the lookups performedby the 'dns' keyword in multidrop mode, providing a way to cope withremote MTAs that identify themselves using their canonical name, whilethey're polled using an alias.When such a server is polled, checks to extract the envelope addressfail, and fetchmail reverts to delivery using the To/Cc/Bccheaders (See below 'Header vs. Envelope addresses').Specifying this option instructs fetchmail to retrieve all the IPaddresses associated with both the poll name and the name used by theremote MTA and to do a comparison of the IP addresses. This comes inhandy in situations where the remote server undergoes frequent canonicalname changes, that would otherwise require modifications to the rcfile.'checkalias' has no effect if 'no dns' is specified in the rcfile.

The 'aka' option is for use with multidrop mailboxes. It allows youto pre-declare a list of DNS aliases for a server. This is anoptimization hack that allows you to trade space for speed. Whenfetchmail, while processing a multidrop mailbox, grovels throughmessage headers looking for names of the mailserver, pre-declaringcommon ones can save it from having to do DNS lookups. Note: the namesyou give as arguments to 'aka' are matched as suffixes -- if you specify(say) 'aka netaxs.com', this will match not just a hostname netaxs.com,but any hostname that ends with '.netaxs.com'; such as (say)pop3.netaxs.com and mail.netaxs.com.

The 'localdomains' option allows you to declare a list of domainswhich fetchmail should consider local. When fetchmail is parsingaddress lines in multidrop modes, and a trailing segment of a hostname matches a declared local domain, that address is passed throughto the listener or MDA unaltered (local-name mappings are notapplied).

If you are using 'localdomains', you may also need to specify 'noenvelope', which disables fetchmail's normal attempt to deducean envelope address from the Received line or X-Envelope-To header orwhatever header has been previously set by 'envelope'. If you set 'noenvelope' in the defaults entry it is possible to undo that inindividual entries by using 'envelope <string>'. As a special case,'envelope "Received"' restores the default parsing ofReceived lines.

The password option requires a string argument, which is the passwordto be used with the entry's server.

The 'preconnect' keyword allows you to specify a shell command to beexecuted just before each timefetchmailestablishes a mailserver connection. This may be useful if you areattempting to set up secure POP connections with the aid ofssh(1).If the command returns a nonzero status, the poll of that mailserverwill be aborted.

Similarly, the 'postconnect' keyword similarly allows you to specify ashell command to be executed just after each time a mailserverconnection is taken down.

The 'forcecr' option controls whether lines terminated by LF only aregiven CRLF termination before forwarding. Strictly speaking RFC821requires this, but few MTAs enforce the requirement so this optionis normally off (only one such MTA, qmail, is in significant use attime of writing).

The 'stripcr' option controls whether carriage returns are strippedout of retrieved mail before it is forwarded. It is normally notnecessary to set this, because it defaults to 'on' (CR strippingenabled) when there is an MDA declared but 'off' (CR strippingdisabled) when forwarding is via SMTP. If 'stripcr' and 'forcecr' areboth on, 'stripcr' will override.

The 'pass8bits' option exists to cope with Microsoft mail programs thatstupidly slap a "Content-Transfer-Encoding: 7bit" on everything. Withthis option off (the default) and such a header present,fetchmaildeclares BODY=7BIT to an ESMTP-capable listener; this causes problems formessages actually using 8-bit ISO or KOI-8 character sets, which willbe garbled by having the high bits of all characters stripped. If'pass8bits' is on,fetchmailis forced to declare BODY=8BITMIME to any ESMTP-capable listener. Ifthe listener is 8-bit-clean (as all the major ones now are) the rightthing will probably result.

The 'dropstatus' option controls whether nonempty Status andX-Mozilla-Status lines are retained in fetched mail (the default) ordiscarded. Retaining them allows your MUA to see what messages (ifany) were marked seen on the server. On the other hand, it canconfuse some new-mail notifiers, which assume that anything with aStatus line in it has been seen. (Note: the empty Status linesinserted by some buggy POP servers are unconditionally discarded.)

The 'dropdelivered' option controls whether Delivered-To headers willbe kept in fetched mail (the default) or discarded. These headers areadded by Qmail and Postfix mailservers in order to avoid mail loops butmay get in your way if you try to "mirror" a mailserver within the samedomain. Use with caution.

The 'mimedecode' option controls whether MIME messages using thequoted-printable encoding are automatically converted into pure 8-bitdata. If you are delivering mail to an ESMTP-capable, 8-bit-cleanlistener (that includes all of the major MTAs like sendmail), thenthis will automatically convert quoted-printable message headers anddata into 8-bit data, making it easier to understand when readingmail. If your e-mail programs know how to deal with MIME messages,then this option is not needed. The mimedecode option is off bydefault, because doing RFC2047 conversion on headers throws awaycharacter-set information and can lead to bad results if the encodingof the headers differs from the body encoding.

The 'idle' option is intended to be used with IMAP servers supportingthe RFC2177 IDLE command extension, but does not strictly require it.If it is enabled, and fetchmail detects that IDLE is supported, anIDLE will be issued at the end of each poll. This will tell the IMAPserver to hold the connection open and notify the client when new mailis available. If IDLE is not supported, fetchmail will simulate it byperiodically issuing NOOP. If you need to poll a link frequently, IDLEcan save bandwidth by eliminating TCP/IP connects and LOGIN/LOGOUTsequences. On the other hand, an IDLE connection will eat almost allof your fetchmail's time, because it will never drop the connectionand allow other polls to occur unless the server times out the IDLE.It also doesn't work with multiple folders; only the first folder willever be polled.

The 'properties' option is an extension mechanism. It takes a stringargument, which is ignored by fetchmail itself. The string argument may beused to store configuration information for scripts which require it.In particular, the output of '--configdump' option will make propertiesassociated with a user entry readily available to a Python script.

Miscellaneous Run Control Options

The words 'here' and 'there' have useful English-likesignificance. Normally 'user eric is esr' would mean thatmail for the remote user 'eric' is to be delivered to 'esr',but you can make this clearer by saying 'user eric there is esr here',or reverse it by saying 'user esr here is eric there'

Legal protocol identifiers for use with the 'protocol' keyword are:

 auto (or AUTO) (legacy, to be removed from future release) pop2 (or POP2) (legacy, to be removed from future release) pop3 (or POP3) sdps (or SDPS) imap (or IMAP) apop (or APOP) kpop (or KPOP)

Legal authentication types are 'any', 'password', 'kerberos','kerberos_v4', 'kerberos_v5' and 'gssapi', 'cram-md5', 'otp', 'msn'(only for POP3), 'ntlm', 'ssh', 'external' (only IMAP).The 'password' type specifiesauthentication by normal transmission of a password (the password may beplain text or subject to protocol-specific encryption as in CRAM-MD5);'kerberos' tells fetchmail to try to get a Kerberos ticket at thestart of each query instead, and send an arbitrary string as thepassword; and 'gssapi' tells fetchmail to use GSSAPI authentication.See the description of the 'auth' keyword for more.

Specifying 'kpop' sets POP3 protocol over port 1109 with Kerberos V4authentication. These defaults may be overridden by later options.

There are some global option statements: 'set logfile'followed by a string sets the same global specified by --logfile. Acommand-line --logfile option will override this. Note that --logfile isonly effective if fetchmail detaches itself from the terminal and thelogfile already exists before fetchmail is run, and it overrides--syslog in this case. Also,'set daemon' sets the poll interval as --daemon does. This can beoverridden by a command-line --daemon option; in particular --daemon~0can be used to force foreground operation. The 'set postmaster'statement sets the address to which multidrop mail defaults if there areno local matches. Finally, 'set syslog' sends log messages tosyslogd(8).

DEBUGGING FETCHMAIL

Fetchmail crashing

There are various ways in that fetchmail may "crash", i. e. stopoperation suddenly and unexpectedly. A "crash" usually refers to anerror condition that the software did not handle by itself. A well-knownfailure mode is the "segmentation fault" or "signal 11" or "SIGSEGV" orjust "segfault" for short. These can be caused by hardware or by softwareproblems. Software-induced segfaults can usually be reproduced easilyand in the same place, whereas hardware-induced segfaults can go away ifthe computer is rebooted, or powered off for a few hours, and can happenin random locations even if you use the software the same way.

For solving hardware-induced segfaults, find the faulty component and repair orreplace it.may help you with details.

For solving software-induced segfaults, the developers may need a "stackbacktrace".

Enabling fetchmail core dumps

By default, fetchmail suppresses core dumps as these might containpasswords and other sensitive information. For debugging fetchmailcrashes, obtaining a "stack backtrace" from a core dump is often thequickest way to solve the problem, and when posting your problem on amailing list, the developers may ask you for a "backtrace".

1. To get useful backtraces, fetchmail needs to be installed withoutgetting stripped of its compilation symbols. Unfortunately, mostbinary packages that are installed are stripped, and core files fromsymbol-stripped programs are worthless. So you may need to recompilefetchmail. On many systems, you can type

 file `which fetchmail`

to find out if fetchmail was symbol-stripped or not. If yours wasunstripped, fine, proceed, if it was stripped, you need to recompile thesource code first. You do not usually need to install fetchmail in orderto debug it.

2. The shell environment that starts fetchmail needs to enable coredumps. The key is the "maximum core (file) size" that can usually beconfigured with a tool named "limit" or "ulimit". See the documentationfor your shell for details. In the popular bash shell, "ulimit -Scunlimited" will allow the core dump.

3. You need to tell fetchmail, too, to allow core dumps. To dothis, run fetchmail with the -d0 -v options. It is often easierto also add --nosyslog -N as well.

Finally, you need to reproduce the crash. You can just start fetchmailfrom the directory where you compiled it by typing ./fetchmail,so the complete command line will start with ./fetchmail -Nvd0--nosyslog and perhaps list your other options.

After the crash, run your debugger to obtain the core dump. Thedebugger will often be GNU GDB, you can then type (adjust paths asnecessary) gdb ./fetchmail fetchmail.core and then, after GDBhas started up and read all its files, type backtrace full, savethe output (copy & paste will do, the backtrace will be read by a human)and then type quit to leave gdb.Note:on some systems, the corefiles have different names, they might contain a number instead of theprogram name, or number and name, but it will usually have "core" aspart of their name.

INTERACTION WITH RFC 822

When trying to determine the originating address of a message,fetchmail looks through headers in the following order:

 Return-Path: Resent-Sender: (ignored if it doesn't contain an @ or !) Sender: (ignored if it doesn't contain an @ or !) Resent-From: From: Reply-To: Apparently-From:

The originating address is used for logging, and to set the MAIL FROMaddress when forwarding to SMTP. This order is intended to copegracefully with receiving mailing list messages in multidrop mode. Theintent is that if a local address doesn't exist, the bounce messagewon't be returned blindly to the author or to the list itself, butrather to the list manager (which is less annoying).

In multidrop mode, destination headers are processed as follows:First, fetchmail looks for the header specified by the 'envelope' optionin order to determine the local recipient address. If the mail isaddressed to more than one recipient, the Received line won't containany information regarding recipient addresses.

Then fetchmail looks for the Resent-To:, Resent-Cc:, and Resent-Bcc:lines. If they exist, they should contain the final recipients andhave precedence over their To:/Cc:/Bcc: counterparts. If the Resent-*lines don't exist, the To:, Cc:, Bcc: and Apparently-To: lines arelooked for. (The presence of a Resent-To: is taken to imply that theperson referred by the To: address has already received the originalcopy of the mail.)

CONFIGURATION EXAMPLES

Note that although there are password declarations in a good manyof the examples below, this is mainly for illustrative purposes.We recommend stashing account/password pairs in your $HOME/.netrcfile, where they can be used not just by fetchmail but by ftp(1) andother programs.

The basic format is:

: poll SERVERNAME protocol PROTOCOL username NAMEpassword PASSWORD

Example:

poll pop.provider.net protocol pop3 username "jsmith" password "secret1"

Or, using some abbreviations:

poll pop.provider.net proto pop3 user "jsmith" password "secret1"

Multiple servers may be listed:

poll pop.provider.net proto pop3 user "jsmith" pass "secret1"poll other.provider.net proto pop2 user "John.Smith" pass "My^Hat"

Here's the same version with more whitespace and some noise words:

poll pop.provider.net proto pop3 user "jsmith", with password secret1, is "jsmith" here;poll other.provider.net proto pop2: user "John.Smith", with password "My^Hat", is "John.Smith" here;

If you need to include whitespace in a parameter string or start thelatter with a number, enclose the string in double quotes. Thus:

poll mail.provider.net with proto pop3: user "jsmith" there has password "4u but u can't krak this" is jws here and wants mda "/bin/mail"

You may have an initial server description headed by the keyword'defaults' instead of 'poll' followed by a name. Such a recordis interpreted as defaults for all queries to use. It may be overwrittenby individual server descriptions. So, you could write:

defaults proto pop3 user "jsmith"poll pop.provider.net pass "secret1"poll mail.provider.net user "jjsmith" there has password "secret2"

It's possible to specify more than one user per server.The 'user' keyword leads off a user description, and every user specificationin a multi-user entry must include it. Here's an example:

poll pop.provider.net proto pop3 port 3111 user "jsmith" with pass "secret1" is "smith" here user jones with pass "secret2" is "jjones" here keep

This associates the local username 'smith' with the pop.provider.netusername 'jsmith' and the local username 'jjones' with thepop.provider.net username 'jones'. Mail for 'jones' is kept on theserver after download.

Here's what a simple retrieval configuration for a multidrop mailboxlooks like:

poll pop.provider.net: user maildrop with pass secret1 to golux 'hurkle'='happy' snark here

This says that the mailbox of account 'maildrop' on the server is amultidrop box, and that messages in it should be parsed for theserver user names 'golux', 'hurkle', and 'snark'. It furtherspecifies that 'golux' and 'snark' have the same name on theclient as on the server, but mail for server user 'hurkle' should bedelivered to client user 'happy'.

Note that fetchmail, until version 6.3.4, did NOT allow fulluser [at] domain specifications here, these would never match.Fetchmail 6.3.5 and newer support user [at] domain specifications onthe left-hand side of a user mapping.

Here's an example of another kind of multidrop connection:

poll pop.provider.net localdomains loonytoons.org toons.org envelope X-Envelope-To user maildrop with pass secret1 to * here

This also says that the mailbox of account 'maildrop' on the server isa multidrop box. It tells fetchmail that any address in theloonytoons.org or toons.org domains (including sub-domain addresses like'joe [at] daffy.loonytoons.org') should be passed through to the local SMTPlistener without modification. Be careful of mail loops if you do this!

Here's an example configuration using ssh and the plugin option. Thequeries are made directly on the stdin and stdout of imapd via ssh.Note that in this setup, IMAP authentication can be skipped.

poll mailhost.net with proto imap: plugin "ssh %h /usr/sbin/imapd" auth ssh; user esr is esr here

THE USE AND ABUSE OF MULTIDROP MAILBOXES

Use the multiple-local-recipients feature with caution -- it can bite.All multidrop features are ineffective in ETRN and ODMR modes.

Also, note that in multidrop mode duplicate mails are suppressed. Apiece of mail is considered duplicate if it has the same message-ID asthe message immediately preceding and more than one addressee. Suchruns of messages may be generated when copies of a message addressedto multiple users are delivered to a multidrop box.

Header vs. Envelope addresses

The fundamental problem is that by having your mailserver toss severalpeoples' mail in a single maildrop box, you may have thrown awaypotentially vital information about who each piece of mail wasactually addressed to (the 'envelope address', as opposed to theheader addresses in the RFC822 To/Cc headers - the Bcc is not availableat the receiving end). This 'envelope address' is the address you needin order to reroute mail properly.

Sometimesfetchmailcan deduce the envelope address. If the mailserver MTA issendmailand the item of mail had just one recipient, the MTA will have writtena 'by/for' clause that gives the envelope addressee into its Receivedheader. But this doesn't work reliably for other MTAs, nor if there ismore than one recipient. By default, fetchmail looks forenvelope addresses in these lines; you can restore this default with-E "Received" or 'envelope Received'.

As a better alternative,some SMTP listeners and/or mail servers insert a headerin each message containing a copy of the envelope addresses. Thisheader (when it exists) is often 'X-Original-To', 'Delivered-To' or'X-Envelope-To'. Fetchmail's assumption about this can be changed withthe -E or 'envelope' option. Note that writing an envelope header ofthis kind exposes the names of recipients (including blind-copyrecipients) to all receivers of the messages, so the upstream must storeone copy of the message per recipient to avoid becoming a privacy problem.

Postfix, since version 2.0, writes an X-Original-To: header whichcontains a copy of the envelope as it was received.

Qmail and Postfix generally write a 'Delivered-To' header upondelivering the message to the mail spool and use it to avoid mail loops.Qmail virtual domains however will prefix the user name with a stringthat normally matches the user's domain. To remove this prefix you canuse the -Q or 'qvirtual' option.

Sometimes, unfortunately, neither of these methods works. That is thepoint when you should contact your ISP and ask them to provide such anenvelope header, and you should not use multidrop in this situation.When they all fail, fetchmail must fall back on the contents of To/Ccheaders (Bcc headers are not available - see below) to try to determinerecipient addressees -- and these are unreliable.In particular, mailing-list software often ships mail with onlythe list broadcast address in the To header.

Note that a future version of fetchmail may remove To/Cc parsing!

Whenfetchmailcannot deduce a recipient address that is local, and the intendedrecipient address was anyone other than fetchmail's invoking user,mail will get lost.This is what makes the multidrop feature risky without proper envelopeinformation.

A related problem is that when you blind-copy a mail message, the Bccinformation is carried only as envelope address (it's removed fromthe headers by the sending mail server, so fetchmail can see it only ifthere is an X-Envelope-To header). Thus, blind-copying to someone whogets mail over a fetchmail multidrop link will fail unless the themailserver host routinely writes X-Envelope-To or an equivalent headerinto messages in your maildrop.

In conclusion, mailing lists and Bcc'd mail can only work if theserver you're fetching from

(1): stores one copy of the message per recipient in your domain and
(2): records the envelope information in a special header (X-Original-To,Delivered-To, X-Envelope-To).

Good Ways To Use Multidrop Mailboxes

Multiple local names can be used to administer a mailing list from theclient side of a fetchmail collection. Suppose your name is'esr', and you want to both pick up your own mail and maintain a mailinglist called (say) "fetchmail-friends", and you want to keep the aliaslist on your client machine.

On your server, you can alias 'fetchmail-friends' to 'esr'; then, inyour .fetchmailrc, declare 'to esr fetchmail-friends here'.Then, when mail including 'fetchmail-friends' as a local addressgets fetched, the list name will be appended to the list ofrecipients your SMTP listener sees. Therefore it will undergo aliasexpansion locally. Be sure to include 'esr' in the local aliasexpansion of fetchmail-friends, or you'll never see mail sent only tothe list. Also be sure that your listener has the "me-too" option set(sendmail's -oXm command-line option or OXm declaration) so your nameisn't removed from alias expansions in messages you send.

This trick is not without its problems, however. You'll begin to seethis when a message comes in that is addressed only to a mailing listyou do not have declared as a local name. Each such messagewill feature an 'X-Fetchmail-Warning' header which is generatedbecause fetchmail cannot find a valid local name in the recipientaddresses. Such messages default (as was described above) to beingsent to the local user running fetchmail, but the program has noway to know that that's actually the right thing.

Bad Ways To Abuse Multidrop Mailboxes

Multidrop mailboxes andfetchmailserving multiple users in daemon mode do not mix. The problem, again, ismail from mailing lists, which typically does not have an individualrecipient address on it. Unlessfetchmailcan deduce an envelope address, such mail will only go to the accountrunning fetchmail (probably root). Also, blind-copied users are verylikely never to see their mail at all.

If you're tempted to usefetchmailto retrieve mail for multiple users from a single mail drop via POP orIMAP, think again (and reread the section on header and envelopeaddresses above). It would be smarter to just let the mail sit in themailserver's queue and use fetchmail's ETRN or ODMR modes to triggerSMTP sends periodically (of course, this means you have to poll morefrequently than the mailserver's expiry period). If you can't arrangethis, try setting up a UUCP feed.

If you absolutely must use multidrop for this purpose, make sureyour mailserver writes an envelope-address header that fetchmail cansee. Otherwise you will lose mail and it will come backto haunt you.

Speeding Up Multidrop Checking

Normally, when multiple users are declaredfetchmailextracts recipient addresses as described above and checks each hostpart with DNS to see if it's an alias of the mailserver. If so, thename mappings described in the "to ... here" declaration are done andthe mail locally delivered.

This is a convenient but also slow method. To speedit up, pre-declare mailserver aliases with 'aka'; these are checkedbefore DNS lookups are done. If you're certain your aka list containsallDNS aliases of the mailserver (and all MX names pointing at it - notethis may change in a future version)you can declare 'no dns' to suppress DNS lookups entirely andonly match against the aka list.

SOCKS

Support for socks4/5 is a compile time configuration option. Oncecompiled in, fetchmail will always use the socks libraries andconfiguration on your system, there are no run-time switches infetchmail - but you can still configure SOCKS: you can specify whichSOCKS configuration file is used in the SOCKS_CONF environmentvariable.

For instance, if you wanted to bypass the SOCKS proxy altogether andhave fetchmail connect directly, you could just passSOCKS_CONF=/dev/null in the environment, for example (add your usualcommand line options - if any - to the end of this line):

env SOCKS_CONF=/dev/null fetchmail

EXIT CODES

To facilitate the use offetchmailin shell scripts, an exit status code is returned to give an indicationof what occurred during a given connection.

The exit codes returned byfetchmailare as follows:

0

One or more messages were successfully retrieved (or, if the -c optionwas selected, were found waiting but not retrieved).

1

There was no mail awaiting retrieval. (There may have been old mail stillon the server but not selected for retrieval.) If you do not want "nomail" to be an error condition (for instance, for cron jobs), use aPOSIX-compliant shell and add

|| [ $? -eq 1 ]

to the end of the fetchmail command line, note that this leaves 0untouched, maps 1 to 0, and maps all other codes to 1. See also item #C8in the FAQ.

2

An error was encountered when attempting to open a socket to retrievemail. If you don't know what a socket is, don't worry about it --just treat this as an 'unrecoverable error'. This error can also bebecause a protocol fetchmail wants to use is not listed in /etc/services.

3

The user authentication step failed. This usually means that a baduser-id, password, or APOP id was specified. Or it may mean that youtried to run fetchmail under circ*mstances where it did not havestandard input attached to a terminal and could not prompt for amissing password.

4

Some sort of fatal protocol error was detected.

5

There was a syntax error in the arguments tofetchmail, or a pre- or post-connect command failed.

6

The run control file had bad permissions.

7

There was an error condition reported by the server. Can alsofire if fetchmail timed out while waiting for the server.

8

Client-side exclusion error. This meansfetchmaileither found another copy of itself already running, or failed in sucha way that it isn't sure whether another copy is running.

9

The user authentication step failed because the server responded "lockbusy". Try again after a brief pause! This error is not implementedfor all protocols, nor for all servers. If not implemented for yourserver, "3" will be returned instead, see above. May be returned whentalking to qpopper or other servers that can respond with "lock busy"or some similar text containing the word "lock".

10

Thefetchmailrun failed while trying to do an SMTP port open or transaction.

11

Fatal DNS error. Fetchmail encountered an error while performinga DNS lookup at startup and could not proceed.

12

BSMTP batch file could not be opened.

13

Poll terminated by a fetch limit (see the --fetchlimit option).

14

Server busy indication.

23

Internal error. You should see a message on standard error withdetails.

24 - 26, 28, 29

These are internal codes and should not appear externally.

Whenfetchmailqueries more than one host, return status is 0 if any querysuccessfully retrieved mail. Otherwise the returned error status isthat of the last host queried.

FILES

~/.fetchmailrc, $HOME/.fetchmailrc, $HOME_ETC/.fetchmailrc, $FETCHMAILHOME/fetchmailrc: default run control file (location can be overridden with environment variables)
~/.fetchids, $HOME/.fetchids, $HOME_ETC/.fetchids, $FETCHMAILHOME/.fetchids: default location of file recording last message UIDs seen per host.(location can be overridden with environment variables)
~/.fetchmail.pid, $HOME/.fetchmail.pid, $HOME_ETC/.fetchmail.pid, $FETCHMAILHOME/fetchmail.pid: default location of lock file to help prevent concurrent runs (non-root mode).(location can be overridden with environment variables)
~/.netrc, $HOME/.netrc, $HOME_ETC/.netrc: your FTP run control file, which (if present) will be searched forpasswords as a last resort before prompting for one interactively.(location can be overridden with environment variables)
/var/run/fetchmail.pid: lock file to help prevent concurrent runs (root mode, Linux systems).
/etc/fetchmail.pid: lock file to help prevent concurrent runs (root mode, systems without /var/run).

ENVIRONMENT

FETCHMAILHOME: If this environment variable is set to a valid andexisting directory name, fetchmail will read $FETCHMAILHOME/fetchmailrc(the dot is missing in this case), $FETCHMAILHOME/.fetchids (keeping its dot) and$FETCHMAILHOME/fetchmail.pid (without dot) rather than from the user's homedirectory. The .netrc file is always looked for in the the invokinguser's home directory (or $HOME_ETC) regardless of FETCHMAILHOME's setting.
FETCHMAILUSER: If this environment variable is set, it is used as the name of thecalling user (default local name) for purposes such as mailing errornotifications. Otherwise, if either the LOGNAME or USER variable iscorrectly set (e.g. the corresponding UID matches the session user ID)then that name is used as the default local name. Otherwisegetpwuid(3) must be able to retrieve a password entry for thesession ID (this elaborate logic is designed to handle the case ofmultiple names per userid gracefully).
FETCHMAIL_DISABLE_CBC_IV_COUNTERMEASURE: (since v6.3.22):If this environment variable is set and not empty, fetchmail will disablea countermeasure against an SSL CBC IV attack (by settingSSL_OP_DONT_INSERT_EMPTY_FRAGMENTS). This is a security risk, but may benecessary for connecting to certain non-standards-conforming servers.See fetchmail's NEWS file and fetchmail-SA-2012-01.txt for details.Earlier fetchmail versions (v6.3.21 and older) used to disable thiscountermeasure, but v6.3.22 no longer does that as a safety precaution.
FETCHMAIL_POP3_FORCE_RETR: (since v6.3.9):If this environment variable is defined at all (even if empty), fetchmailwill forgo the POP3 TOP command and always use RETR. This can beused as a workaround when TOP does not work properly.
FETCHMAIL_INCLUDE_DEFAULT_X509_CA_CERTS: (since v6.3.17):If this environment variable is set and not empty, fetchmail will always loadthe default X.509 trusted certificate locations for SSL/TLS CA certificates,even if --sslcertfile and --sslcertpath are given.The latter locations take precedence over the system default locations.This is useful in case there are broken certificates in the system directoriesand the user has no administrator privileges to remedy the problem.
HOME: (documented since 6.4.1):This variable is nomally set to the user's home directory. If it is setto a different directory than what is the password database, HOME takesprecedence.
HOME_ETC: (documentation corrected to match behaviour code since 6.4.1):If the HOME_ETC variable is set, it will override fetchmail's idea of $HOME,i. e. fetchmail will read .fetchmailrc, .fetchids, .fetchmail.pid and .netrcfrom $HOME_ETC instead of $HOME (or if HOME is also unset,from the passwd file's home directory location).
If HOME_ETC and FETCHMAILHOME are both set, FETCHMAILHOME takes prececenceand HOME_ETC will be ignored.
SOCKS_CONF: (only if SOCKS support is compiled in) this variable is used by thesocks library to find out which configuration file it should read. Setthis to /dev/null to bypass the SOCKS proxy.

SIGNALS

If a fetchmail daemon is running as root, SIGUSR1 wakes it up from itssleep phase and forces a poll of all non-skipped servers. For compatibilityreasons, SIGHUP can also be used in 6.3.X but may not be available in futurefetchmail versions.

If fetchmail is running in daemon mode as non-root, use SIGUSR1 to wakeit (this is so SIGHUP due to logout can retain the default action of killingit).

Running fetchmail in foreground while a background fetchmail isrunning will do whichever of these is appropriate to wake it up.

BUGS, LIMITATIONS, AND KNOWN PROBLEMS

Please check the NEWS file that shipped with fetchmail for moreknown bugs than those listed here.

Fetchmail cannot handle user names that contain blanks after a "@"character, for instance "demonstr@ti on". These are rather uncommon andonly hurt when using UID-based --keep setups, so the 6.3.X versions offetchmail won't be fixed.

Fetchmail cannot handle configurations where you have multiple accountsthat use the same server name and the same login. Any user [at] servercombination must be unique.

The assumptions that the DNS and in particular the checkalias optionsmake are not often sustainable. For instance, it has become uncommon foran MX server to be a POP3 or IMAP server at the same time. Therefore theMX lookups may go away in a future release.

The mda and plugin options interact badly. In order to collect errorstatus from the MDA, fetchmail has to change its normal signalhandling so that dead plugin processes don't get reaped until the endof the poll cycle. This can cause resource starvation if too manyzombies accumulate. So either don't deliver to a MDA using plugins orrisk being overrun by an army of undead.

The --interface option does not support IPv6 and it is doubtful if itever will, since there is no portable way to query interface IPv6addresses.

The RFC822 address parser used in multidrop mode chokes on some@-addresses that are technically legal but bizarre. Strange uses ofquoting and embedded comments are likely to confuse it.

In a message with multiple envelope headers, only the last oneprocessed will be visible to fetchmail.

Use of some of these protocols requires that the program sendunencrypted passwords over the TCP/IP connection to the mailserver.This creates a risk that name/password pairs might be snaffled with apacket sniffer or more sophisticated monitoring software. Under Linuxand FreeBSD, the --interface option can be used to restrict polling toavailability of a specific interface device with a specific local orremote IP address, but snooping is still possible if (a) either hosthas a network device that can be opened in promiscuous mode, or (b)the intervening network link can be tapped. We recommend the use ofssh(1)tunnelling to not only shroud your passwords but encrypt the entireconversation.

Use of the %F or %T escapes in an mda option could open a securityhole, because they pass text manipulable by an attacker to a shellcommand. Potential shell characters are replaced by '_' beforeexecution. The hole is further reduced by the fact that fetchmailtemporarily discards any suid privileges it may have while running theMDA. For maximum safety, however, don't use an mda command containing%F or %T when fetchmail is run from the root account itself.

Fetchmail's method of sending bounces due to errors or spam-blocking andspam bounces requires that port 25 of localhost be available for sendingmail via SMTP.

If you modify ~/.fetchmailrc while a background instance isrunning and break the syntax, the background instance will die silently.Unfortunately, it can't die noisily because we don't yet know whethersyslog should be enabled. On some systems, fetchmail dies quietly evenif there is no syntax error; this seems to have something to do withbuggy terminal ioctl code in the kernel.

The -f~- option (reading a configuration from stdin) is incompatiblewith the plugin option.

The 'principal' option only handles Kerberos IV, not V.

Interactively entered passwords are truncated after 63 characters. Ifyou really need to use a longer password, you will have to use aconfiguration file.

A backslash as the last character of a configuration file will beflagged as a syntax error rather than ignored.

The BSMTP error handling is virtually nonexistent and may leave brokenmessages behind.

Send comments, bug reports, gripes, and the like to the

Anis available at the fetchmail home page, it should also accompany yourinstallation.

AUTHOR

Fetchmail is currently maintained by Matthias Andree and Rob Funk withmajor assistance from Sunil Shetye (for code) and Rob MacGregor (for themailing lists).

Most of the code is from. Too many other people to name here have contributed code and patches.

This program is descended from and replacespopclient,by; the internals have become quite different, but some of its interfacedesign is directly traceable to that ancestral program.

This manual page has been improved by Matthias Andree, R. HannesBeinert, and Héctor García.

APPLICABLE STANDARDS

Note that this list is just a collection of references and not astatement as to the actual protocol conformance or requirements infetchmail.

SMTP/ESMTP:: RFC 821, RFC 2821, RFC 1869, RFC 1652, RFC 1870, RFC 1983, RFC 1985,RFC 2554.
mail:: RFC 822, RFC 2822, RFC 1123, RFC 1892, RFC 1894.
POP2:: RFC 937
POP3:: RFC 1081, RFC 1225, RFC 1460, RFC 1725, RFC 1734, RFC 1939, RFC 1957,RFC 2195, RFC 2449.
APOP:: RFC 1939.
RPOP:: RFC 1081, RFC 1225.
IMAP2/IMAP2BIS:: RFC 1176, RFC 1732.
IMAP4/IMAP4rev1:: RFC 1730, RFC 1731, RFC 1732, RFC 2060, RFC 2061, RFC 2195, RFC 2177,RFC 2683.
ETRN:: RFC 1985.
ODMR/ATRN:: RFC 2645.
OTP:: RFC 1938.
LMTP:: RFC 2033.
GSSAPI:: RFC 1508, RFC 1734,
TLS:: RFC 2595.

Pages related to fetchmail

fetchmailrc (1) - fetch mail from a POP, IMAP, ETRN, or ODMR-capable server
fetchlog (1) - fetch and convert new messages of a logfile
fetchzone (1) - get dns zone from server
fet (1) - free timetabling
feathers (1) - a simple source-level debugger for CHICKEN Scheme
features-matching (1) - Demonstration of image feature matching

Keyword	Opt	Mode	Function

set daemon	-d		Set a background poll interval in seconds.
set postmaster			Give the name of the last-resort mail recipient (default: user runningfetchmail, "postmaster" if run by the root user)
set bouncemail			Direct error mail to the sender (default)
set no bouncemail			Direct error mail to the local postmaster (as per the 'postmaster'global option above).
set no spambounce			Do not bounce spam-blocked mail (default).
set spambounce			Bounce blocked spam-blocked mail (as per the 'antispam' user option)back to the destination as indicated by the 'bouncemail' global option.Warning: Do not use this to bounce spam back to the sender - most spamis sent with false sender address and thus this option hurts innocentbystanders.
set no softbounce			Delete permanently undeliverable mail. It is recommended to use thisoption if the configuration has been thoroughly tested.
set softbounce			Keep permanently undeliverable mail as though a temporary error hadoccurred (default).
set logfile	-L		Name of a file to append error and status messages to. Only effectivein daemon mode and if fetchmail detaches. If effective, overrides setsyslog.
set pidfile	-p		Name of the PID file.
set idfile	-i		Name of the file to store UID lists in.
set syslog			Do error logging through syslog(3). May be overridden by setlogfile.
set no syslog			Turn off error logging through syslog(3). (default)
set properties			String value that is ignored by fetchmail (may be used by extensionscripts).

fetchmail: fetch mail from a POP, IMAP, ETRN, or ODMR-capable server - Linux Manuals (1) (2024)