2 .\" ** The above line should force tbl to be used as a preprocessor **
4 .\" Manual page in man(7) format with tbl(1) macros for fetchmail
6 .\" For license terms, see the file COPYING in this directory.
8 .TH fetchmail 1 "fetchmail 6.3.5" "fetchmail" "fetchmail reference manual"
10 fetchmail \- fetch mail from a POP, IMAP, ETRN, or ODMR-capable server
13 \fBfetchmail\fR [\fIoption...\fR] [\fImailserver...\fR]
19 is a mail-retrieval and forwarding utility; it fetches mail from
20 remote mailservers and forwards it to your local (client) machine's
21 delivery system. You can then handle the retrieved mail using normal
22 mail user agents such as \fImutt\fR(1), \fIelm\fR(1) or \fIMail\fR(1).
23 The \fIfetchmail\fR utility can be run in a daemon mode to repeatedly
24 poll one or more systems at a specified interval.
28 program can gather mail from servers supporting any of the common
29 mail-retrieval protocols: POP2 (legacy, to be removed from future
30 release), POP3, IMAP2bis, IMAP4, and IMAP4rev1.
31 It can also use the ESMTP ETRN extension and ODMR. (The RFCs describing all
32 these protocols are listed at the end of this manual page.)
36 is primarily intended to be used over on-demand TCP/IP links (such as
37 SLIP or PPP connections), it may also be useful as a message transfer
38 agent for sites which refuse for security reasons to permit
39 (sender-initiated) SMTP transactions with sendmail.
43 is used with a POP or an IMAP server, it has two fundamental modes of
44 operation for each user account from which it retrieves mail:
45 \fIsingledrop\fR- and \fImultidrop\fR-mode. In singledrop-mode,
47 assumes that all messages in the user's account are intended for a single
48 recipient. An individual mail message will not be inspected for recipient
49 information, rather, the identity of the recipient will either default to
50 the local user currently executing \fIfetchmail\fR,
51 or else will need to be explicitly specified in the configuration file.
52 Singledrop-mode is used when the fetchmailrc configuration contains at
53 most a single local user specification for a given server account.
57 is not able to assume that there is only a single recipient, but rather
58 that the mail server account actually contains mail intended for any
59 number of different recipients. Therefore,
61 must attempt to deduce the proper "envelope recipient" from the mail
62 headers of each message. In this mode of operation
64 almost resembles an MTA, however it is important to note that neither
65 the POP nor IMAP protocols were intended for use in this fashion, and
66 hence envelope information is not directly available. Instead,
68 must resort to a process of informed guess-work in an attempt to
69 discover the true envelope recipient of a message. Even if this
70 information is present in the headers, the process can
71 be error-prone and is dependent upon the specific mail server used
72 for mail retrieval. Multidrop-mode is used when more than one local
73 user is specified for a particular server account in the configuration
74 file. Note that the forgoing discussion of singledrop- and
75 multidrop-modes does not apply to the ESMTP ETRN or ODMR retrieval
76 methods, since they are based upon the SMTP protocol which
77 specifically provides the envelope recipient to \fIfetchmail\fR.
79 As each message is retrieved \fIfetchmail\fR normally delivers it via SMTP to
80 port 25 on the machine it is running on (localhost), just as though it
81 were being passed in over a normal TCP/IP link. \fIfetchmail\fR provides
82 the SMTP server with an envelope recipient derived in the manner described
83 previously. The mail will then be
84 delivered locally via your system's MDA (Mail Delivery Agent, usually
85 \fIsendmail\fR(8) but your system may use a different one such
86 as \fIsmail\fR, \fImmdf\fR, \fIexim\fR, \fIpostfix\fR, or \fIqmail\fR). All the
87 delivery-control mechanisms (such as \fI.forward\fR files) normally
88 available through your system MDA and local delivery agents will
89 therefore work automatically.
91 If no port 25 listener is available, but your fetchmail configuration
92 was told about a reliable local MDA, it will use that MDA for local
97 is available, it will assist you in setting up and editing a
98 fetchmailrc configuration. It runs under the X window system and
99 requires that the language Python and the Tk toolkit be present on your
100 system. If you are first setting up fetchmail for single-user mode, it
101 is recommended that you use Novice mode. Expert mode provides complete
102 control of fetchmail configuration, including the multidrop features.
103 In either case, the 'Autoprobe' button will tell you the most capable
104 protocol a given mailserver supports, and warn you of potential problems
107 .SH GENERAL OPERATION
110 is controlled by command-line options and a run control file,
111 .IR ~/.fetchmailrc\fR ,
112 the syntax of which we describe in a later section (this file is what
113 the \fIfetchmailconf\fR program edits). Command-line options override
117 Each server name that you specify following the options on the
118 command line will be queried. If you don't specify any servers
119 on the command line, each 'poll' entry in your
121 file will be queried.
123 To facilitate the use of
125 in scripts and pipelines, it returns an appropriate exit code upon
126 termination -- see EXIT CODES below.
128 The following options modify the behavior of \fIfetchmail\fR. It is
129 seldom necessary to specify any of these once you have a
130 working \fI.fetchmailrc\fR file set up.
132 Almost all options have a corresponding keyword which can be used to
137 Some special options are not covered here, but are documented instead
138 in sections on AUTHENTICATION and DAEMON MODE which follow.
142 Displays the version information for your copy of
144 No mail fetch is performed.
145 Instead, for each server specified, all the option information
146 that would be computed if
148 were connecting to that server is displayed. Any non-printables in
149 passwords or other string names are shown as backslashed C-like
150 escape sequences. This option is useful for verifying that your
151 options are set the way you want them.
154 Return a status code to indicate whether there is mail waiting,
155 without actually fetching or deleting mail (see EXIT CODES below).
156 This option turns off daemon mode (in which it would be useless). It
157 doesn't play well with queries to multiple sites, and doesn't work
158 with ETRN or ODMR. It will return a false positive if you leave read but
159 undeleted mail in your server mailbox and your fetch protocol can't
160 tell kept messages from new ones. This means it will work with IMAP,
161 not work with POP2, and may occasionally flake out under POP3.
164 Silent mode. Suppresses all progress/status messages that are
165 normally echoed to standard output during a fetch (but does not
166 suppress actual error messages). The \-\-verbose option overrides this.
169 Verbose mode. All control messages passed between
171 and the mailserver are echoed to stdout. Overrides \-\-silent.
172 Doubling this option (\-v \-v) causes extra diagnostic information
176 .B \-a | \-\-all | (since v6.3.3) \-\-fetchall
178 Retrieve both old (seen) and new messages from the mailserver. The
179 default is to fetch only messages the server has not marked seen.
180 Under POP3, this option also forces the use of RETR rather than TOP.
181 Note that POP2 retrieval behaves as though \-\-all is always on (see
182 RETRIEVAL FAILURE MODES below) and this option does not work with ETRN
183 or ODMR. While the \-a and \-\-all command-line and fetchall rcfile
184 options have been supported for a long time, the \-\-fetchall
185 command-line option was added in v6.3.3.
189 Keep retrieved messages on the remote mailserver. Normally, messages
190 are deleted from the folder on the mailserver after they have been retrieved.
193 option causes retrieved messages to remain in your folder on the
194 mailserver. This option does not work with ETRN or ODMR.
198 Delete retrieved messages from the remote mailserver. This
199 option forces retrieved mail to be deleted. It may be useful if
200 you have specified a default of \fBkeep\fR in your
201 \&\fI.fetchmailrc\fR. This option is forced on with ETRN and ODMR.
204 POP3/IMAP only. This is a dangerous option and can cause mail loss when
205 used improperly. It deletes old (seen) messages from the mailserver
206 before retrieving new messages. \fBWarning:\fR This can cause mail loss if
207 you check your mail with other clients than fetchmail, and cause
208 fetchmail to delete a message it had never fetched before. It can also
209 cause mail loss if the mail server marks the message seen after
210 retrieval (IMAP2 servers). You should probably not use this option in your
211 configuration file. If you use it with POP3, you must use the 'uidl'
212 option. What you probably want is the default setting: if you don't
213 specify '\-k', then fetchmail will automatically delete messages after
217 POP3/IMAP only, since version 6.3.0. Delete oversized messages from the
218 mailserver before retrieving new messages. The size limit should be
219 separately specified with the \-\-limit option. This option does not
220 work with ETRN or ODMR.
221 .SS Protocol and Query Options
223 .B \-p <proto> | \-\-proto <proto> | \-\-protocol <proto>
224 (Keyword: proto[col])
225 Specify the protocol to use when communicating with the remote
226 mailserver. If no protocol is specified, the default is AUTO.
228 may be one of the following:
231 Tries IMAP, POP3, and POP2 (skipping any of these for which support
232 has not been compiled in).
234 Post Office Protocol 2 (legacy, to be removed from future release)
236 Post Office Protocol 3
238 Use POP3 with old-fashioned MD5-challenge authentication.
240 Use POP3 with RPOP authentication.
242 Use POP3 with Kerberos V4 authentication on port 1109.
244 Use POP3 with Demon Internet's SDPS extensions.
246 IMAP2bis, IMAP4, or IMAP4rev1 (\fIfetchmail\fR automatically detects their capabilities).
248 Use the ESMTP ETRN option.
250 Use the the On-Demand Mail Relay ESMTP profile.
253 All these alternatives work in basically the same way (communicating
254 with standard server daemons to fetch mail already delivered to a
255 mailbox on the server) except ETRN and ODMR. The ETRN mode
256 allows you to ask a compliant ESMTP server (such as BSD sendmail at
257 release 8.8.0 or higher) to immediately open a sender-SMTP connection
258 to your client machine and begin forwarding any items addressed to
259 your client machine in the server's queue of undelivered mail. The
260 ODMR mode requires an ODMR-capable server and works similarly to
261 ETRN, except that it does not require the client machine to have
266 Force UIDL use (effective only with POP3). Force client-side tracking
267 of 'newness' of messages (UIDL stands for "unique ID listing" and is
268 described in RFC1939). Use with 'keep' to use a mailbox as a baby
269 news drop for a group of users. The fact that seen messages are skipped
270 is logged, unless error logging is done through syslog while running in
271 daemon mode. Note that fetchmail may automatically enable this option
272 depending on upstream server capabilities. Note also that this option
273 may be removed and forced enabled in a future fetchmail version. See
276 .B \-\-idle (since 6.3.3)
278 Enable IDLE use (effective only with IMAP). Note that this works with
279 only one folder at a given time. While the idle rcfile keyword had been
280 supported for a long time, the \-\-idle command-line option was added in
283 .B \-P <portnumber> | \-\-service <servicename>
284 (Keyword: service) Since version 6.3.0.
285 The service option permits you to specify a service name to connect to.
286 You can specify a decimal port number here, if your services database
287 lacks the required service-port assignments. See the FAQ item R12 and
288 the \-\-ssl documentation for details. This replaces the older \-\-port
291 .B \-\-port <portnumber>
293 Obsolete version of \-\-service that does not take service names.
295 this option may be removed from a future version.
297 .B \-\-principal <principal>
299 The principal option permits you to specify a service principal for
300 mutual authentication. This is applicable to POP3 or IMAP with Kerberos
303 .B \-t <seconds> | \-\-timeout <seconds>
305 The timeout option allows you to set a server-nonresponse
306 timeout in seconds. If a mailserver does not send a greeting message
307 or respond to commands for the given number of seconds,
308 \fIfetchmail\fR will hang up on it. Without such a timeout
309 \fIfetchmail\fR might hang up indefinitely trying to fetch mail from a
310 down host. This would be particularly annoying for a \fIfetchmail\fR
311 running in background. There is a default timeout which fetchmail\~\-V
312 will report. If a given connection receives too many timeouts in
313 succession, fetchmail will consider it wedged and stop retrying,
314 the calling user will be notified by email if this happens.
316 .B \-\-plugin <command>
317 (Keyword: plugin) The plugin option allows you to use an external
318 program to establish the TCP connection. This is useful if you want
319 to use socks, SSL, ssh, or need some special firewalling setup. The
320 program will be looked up in $PATH and can optionally be passed the
321 hostname and port as arguments using "%h" and "%p" respectively (note
322 that the interpolation logic is rather primitive, and these token must
323 be bounded by whitespace or beginning of string or end of string).
324 Fetchmail will write to the plugin's stdin and read from the plugin's
327 .B \-\-plugout <command>
329 Identical to the plugin option above, but this one is used for the SMTP
330 connections (which will probably not need it, so it has been separated
333 .B \-r <name> | \-\-folder <name>
335 Causes a specified non-default mail folder on the mailserver (or
336 comma-separated list of folders) to be retrieved. The syntax of the
337 folder name is server-dependent. This option is not available under
341 (Keyword: tracepolls)
342 Tell fetchmail to poll trace information in the form 'polling %s
343 account %s' and 'folder %s' to the Received line it generates,
344 where the %s parts are replaced by the user's remote name, the poll
345 label, and the folder (mailbox) where available (the Received header
346 also normally includes the server's true name). This can be used to
347 facilitate mail filtering based on the account it is being received
348 from. The folder information is written only since version 6.3.4.
352 Causes the connection to the mail server to be encrypted via SSL. Connect
353 to the server using the specified base protocol over a connection secured
354 by SSL. SSL support must be present at the server.
356 Note that fetchmail may still try to negotiate TLS even if this option
357 is not given. You can use the \-\-sslproto option to defeat this
358 behavior or tell fetchmail to negotiate a particular SSL protocol.
360 If no port is specified, the connection is attempted to the well known
361 port of the SSL version of the base protocol. This is generally a
362 different port than the port used by the base protocol. For IMAP, this
363 is port 143 for the clear protocol and port 993 for the SSL secured
364 protocol, for POP3, it is port 110 for the clear text and port 995 for
365 the encrypted variant.
367 If your system lacks the corresponding entries from /etc/services, see
368 the \-\-service option and specify the numeric port number as given in
369 the previous paragraph (unless your ISP had directed you to different
370 ports, which is uncommon however).
372 .B \-\-sslcert <name>
374 Specifies the file name of the client side public SSL certificate. Some
375 SSL encrypted servers may require client side keys and certificates for
376 authentication. In most cases, this is optional. This specifies
377 the location of the public key certificate to be presented to the server
378 at the time the SSL session is established. It is not required (but may
379 be provided) if the server does not require it. Some servers may
380 require it, some servers may request it but not require it, and some
381 servers may not request it at all. It may be the same file
382 as the private key (combined key and certificate file) but this is not
387 Specifies the file name of the client side private SSL key. Some SSL
388 encrypted servers may require client side keys and certificates for
389 authentication. In most cases, this is optional. This specifies
390 the location of the private key used to sign transactions with the server
391 at the time the SSL session is established. It is not required (but may
392 be provided) if the server does not require it. Some servers may
393 require it, some servers may request it but not require it, and some
394 servers may not request it at all. It may be the same file
395 as the public key (combined key and certificate file) but this is not
396 recommended. If a password is required to unlock the key, it will be
397 prompted for at the time just prior to establishing the session to the
398 server. This can cause some complications in daemon mode.
400 .B \-\-sslproto <name>
402 Forces an SSL protocol. Possible values are '\fBssl2\fR',
403 \&'\fBssl3\fR', '\fBssl23\fR', and '\fBtls1\fR'. Try this if the default
404 handshake does not work for your server. To defeat automatic TLSv1
405 negotiation when the server advertises STARTTLS or STLS, use \fB''\fR or
406 \&'\fBssl23\fR'. The default is to try appropriate protocols depending
411 Causes fetchmail to strictly check the server certificate against a set of
412 local trusted certificates (see the \fBsslcertpath\fR option). If the server
413 certificate is not signed by one of the trusted ones (directly or indirectly),
414 the SSL connection will fail, regardless of the \fBsslfingerprint\fR
415 option. This checking should prevent man-in-the-middle attacks against
416 the SSL connection. Note that CRLs are seemingly not currently supported
417 by OpenSSL in certificate verification! Your system clock should be
418 reasonably accurate when using this option.
420 Note that this optional behavior may become default behavior in future
423 .B \-\-sslcertpath <directory>
424 (Keyword: sslcertpath)
425 Sets the directory fetchmail uses to look up local certificates. The default
426 is your OpenSSL default one. The directory must be hashed as OpenSSL expects
427 it - every time you add or modify a certificate in the directory, you need
428 to use the \fBc_rehash\fR tool (which comes with OpenSSL in the tools/
431 .B \-\-sslfingerprint <fingerprint>
432 (Keyword: sslfingerprint)
433 Specify the fingerprint of the server key (an MD5 hash of the key) in
434 hexadecimal notation with colons separating groups of two digits. The letter
435 hex digits must be in upper case. This is the default format OpenSSL uses,
436 and the one fetchmail uses to report the fingerprint when an SSL connection
437 is established. When this is specified, fetchmail will compare the server key
438 fingerprint with the given one, and the connection will fail if they do not
439 match regardless of the \fBsslcertck\fR setting.
440 This can be used to prevent man-in-the-middle attacks, but the finger
441 print from the server needs to be obtained or verified over a secure
442 channel, and certainly not over the same Internet connection that
445 Using this option will prevent printing certificate verification errors
446 as long as \-\-sslcertck is unset.
448 To obtain the fingerprint of a certificate stored in the file cert.pem,
452 openssl x509 \-in cert.pem \-noout \-md5 \-fingerprint
457 .SS Delivery Control Options
459 .B \-S <hosts> | \-\-smtphost <hosts>
460 (Keyword: smtp[host])
461 Specify a hunt list of hosts to forward mail to (one or more
462 hostnames, comma-separated). Hosts are tried in list order; the first
463 one that is up becomes the forwarding target for the current run. If
464 this option is not specified, 'localhost' is used as the default.
465 Each hostname may have a port number following the host name. The
466 port number is separated from the host name by a slash; the default
467 port is "smtp". If you specify an absolute path name (beginning with
468 a /), it will be interpreted as the name of a UNIX socket accepting
469 LMTP connections (such as is supported by the Cyrus IMAP daemon)
473 \-\-smtphost server1,server2/2525,server3,/var/imap/socket/lmtp
476 This option can be used with ODMR, and will make fetchmail a relay
477 between the ODMR server and SMTP or LMTP receiver.
479 .B \-\-fetchdomains <hosts>
480 (Keyword: fetchdomains)
481 In ETRN or ODMR mode, this option specifies the list of domains the
482 server should ship mail for once the connection is turned around. The
483 default is the FQDN of the machine running
486 .B \-D <domain> | \-\-smtpaddress <domain>
487 (Keyword: smtpaddress) Specify the domain to be appended to addresses
488 in RCPT TO lines shipped to SMTP. When this is not specified, the name
489 of the SMTP server (as specified by \-\-smtphost) is used for SMTP/LMTP
490 and 'localhost' is used for UNIX socket/BSMTP.
492 .B \-\-smtpname <user@domain>
494 Specify the domain and user to be put in RCPT TO lines shipped to SMTP.
495 The default user is the current local user.
497 .B \-Z <nnn> | \-\-antispam <nnn[, nnn]...>
499 Specifies the list of numeric SMTP errors that are to be interpreted
500 as a spam-block response from the listener. A value of \-1 disables
501 this option. For the command-line option, the list values should
504 .B \-m <command> | \-\-mda <command>
505 (Keyword: mda) You can force mail to be passed to an MDA directly
506 (rather than forwarded to port 25) with the \-\-mda or \-m option. To
507 avoid losing mail, use this option only with MDAs like maildrop or
508 MTAs like sendmail that return a nonzero status on disk-full and other
509 resource-exhaustion errors; the nonzero status tells fetchmail that
510 delivery failed and prevents the message from being deleted off the
511 server. If \fIfetchmail\fR is running as root, it sets its user id to
512 that of the target user while delivering mail through an MDA. Some
513 possible MDAs are "/usr/sbin/sendmail \-i \-f %F \-\- %T" (\fBNote:\fR
514 some several older or vendor sendmail versions mistake \-\- for an
515 address, rather than an indicator to mark the end of the option arguments),
516 "/usr/bin/deliver" and "/usr/bin/maildrop \-d %T". Local delivery
517 addresses will be inserted into the MDA command wherever you place a
518 %T; the mail message's From address will be inserted where you place
519 an %F. \fBDO NOT ENCLOSE THE %F OR %T STRING IN SINGLE QUOTES!\fR For
520 both %T and %F, fetchmail encloses the addresses in single quotes ('),
521 after removing any single quotes they may contain, before the MDA
522 command is passed to the shell. Do \fINOT\fR use an MDA invocation
523 like "sendmail \-i \-t" that dispatches on the contents of To/Cc/Bcc, it
524 will create mail loops and bring the just wrath of many postmasters
525 down upon your head. Also, do \fInot\fR try to combine multidrop
526 mode with an MDA such as maildrop or procmail that can only accept one
527 address; you will lose mail.
529 A word of warning: the well-known
531 package is very hard to configure properly, it has a very nasty "fall
532 through to the next rule" behavior on delivery errors (even temporary
533 ones, such as out of disk space if another user's mail daemon copies the
534 mailbox around to purge old messages), so your mail will end up in the
535 wrong mailbox sooner or later. The proper procmail configuration is
536 outside the scope of this document though. Using
538 is usually much easier, and many users find the filter syntax used by
539 maildrop easier to understand.
544 Cause delivery via LMTP (Local Mail Transfer Protocol). A service
545 host and port \fBmust\fR be explicitly specified on each host in the
546 smtphost hunt list (see above) if this option is selected; the default
547 port 25 will (in accordance with RFC 2033) not be accepted.
549 .B \-\-bsmtp <filename>
551 Append fetched mail to a BSMTP file. This simply contains the SMTP
552 commands that would normally be generated by fetchmail when passing
553 mail to an SMTP listener daemon. An argument of '\-' causes the mail
554 to be written to standard output. Note that fetchmail's
555 reconstruction of MAIL FROM and RCPT TO lines is not guaranteed
556 correct; the caveats discussed under THE USE AND ABUSE OF MULTIDROP
557 MAILBOXES below apply.
558 .SS Resource Limit Control Options
560 .B \-l <maxbytes> | \-\-limit <maxbytes>
561 (Keyword: limit) Takes a maximum octet size argument. Messages larger
562 than this size will not be fetched and will be left on the server (in
563 foreground sessions, the progress messages will note that they are
564 "oversized"). If the fetch protocol permits (in particular, under
565 IMAP or POP3 without the fetchall option) the message will not be
568 An explicit \-\-limit of 0 overrides any limits set in your
569 run control file. This option is intended for those needing to
570 strictly control fetch time due to expensive and variable phone rates.
572 Combined with \-\-limitflush, it can be used to delete oversized
573 messages waiting on a server. In daemon mode, oversize notifications
574 are mailed to the calling user (see the \-\-warnings option). This
575 option does not work with ETRN or ODMR.
577 .B \-w <interval> | \-\-warnings <interval>
579 Takes an interval in seconds. When you call
581 with a 'limit' option in daemon mode, this controls the interval at
582 which warnings about oversized messages are mailed to the calling user
583 (or the user specified by the 'postmaster' option). One such
584 notification is always mailed at the end of the the first poll that
585 the oversized message is detected. Thereafter, re-notification is
586 suppressed until after the warning interval elapses (it will take
587 place at the end of the first following poll).
589 .B \-b <count> | \-\-batchlimit <count>
590 (Keyword: batchlimit)
591 Specify the maximum number of messages that will be shipped to an SMTP
592 listener before the connection is deliberately torn down and rebuilt
593 (defaults to 0, meaning no limit). An explicit \-\-batchlimit of 0
594 overrides any limits set in your run control file. While
595 \fBsendmail\fR(8) normally initiates delivery of a message immediately
596 after receiving the message terminator, some SMTP listeners are not so
597 prompt. MTAs like \fIsmail\fR(8) may wait till the
598 delivery socket is shut down to deliver. This may produce annoying
599 delays when \fIfetchmail\fR is processing very large batches. Setting
600 the batch limit to some nonzero size will prevent these delays. This
601 option does not work with ETRN or ODMR.
603 .B \-B <number> | \-\-fetchlimit <number>
604 (Keyword: fetchlimit)
605 Limit the number of messages accepted from a given server in a single
606 poll. By default there is no limit. An explicit \-\-fetchlimit of 0
607 overrides any limits set in your run control file.
608 This option does not work with ETRN or ODMR.
610 .B \-\-fetchsizelimit <number>
611 (Keyword: fetchsizelimit)
612 Limit the number of sizes of messages accepted from a given server in
613 a single transaction. This option is useful in reducing the delay in
614 downloading the first mail when there are too many mails in the
615 mailbox. By default, the limit is 100. If set to 0, sizes of all
616 messages are downloaded at the start.
617 This option does not work with ETRN or ODMR. For POP3, the only valid
620 .B \-\-fastuidl <number>
622 Do a binary instead of linear search for the first unseen UID. Binary
623 search avoids downloading the UIDs of all mails. This saves time
624 (especially in daemon mode) where downloading the same set of UIDs in
625 each poll is a waste of bandwidth. The number 'n' indicates how rarely
626 a linear search should be done. In daemon mode, linear search is used
627 once followed by binary searches in 'n-1' polls if 'n' is greater than
628 1; binary search is always used if 'n' is 1; linear search is always
629 used if 'n' is 0. In non-daemon mode, binary search is used if 'n' is
630 1; otherwise linear search is used. The default value of 'n' is 4.
631 This option works with POP3 only.
633 .B \-e <count> | \-\-expunge <count>
635 Arrange for deletions to be made final after a given number of
636 messages. Under POP2 or POP3, fetchmail cannot make deletions final
637 without sending QUIT and ending the session -- with this option on,
638 fetchmail will break a long mail retrieval session into multiple
639 sub-sessions, sending QUIT after each sub-session. This is a good
640 defense against line drops on POP3 servers that do not do the
641 equivalent of a QUIT on hangup. Under IMAP,
643 normally issues an EXPUNGE command after each deletion in order to
644 force the deletion to be done immediately. This is safest when your
645 connection to the server is flaky and expensive, as it avoids
646 resending duplicate mail after a line hit. However, on large
647 mailboxes the overhead of re-indexing after every message can slam the
648 server pretty hard, so if your connection is reliable it is good to do
649 expunges less frequently. Also note that some servers enforce a delay
650 of a few seconds after each quit, so fetchmail may not be able to get
651 back in immediately after an expunge -- you may see "lock busy" errors
652 if this happens. If you specify this option to an integer N,
655 to only issue expunges on every Nth delete. An argument of zero
656 suppresses expunges entirely (so no expunges at all will be done until
657 the end of run). This option does not work with ETRN or ODMR.
658 .SS Authentication Options
660 .B \-u <name> | \-\-user <name> | \-\-username <name>
661 (Keyword: user[name])
662 Specifies the user identification to be used when logging in to the mailserver.
663 The appropriate user identification is both server and user-dependent.
664 The default is your login name on the client machine that is running
666 See USER AUTHENTICATION below for a complete description.
668 .B \-I <specification> | \-\-interface <specification>
670 Require that a specific interface device be up and have a specific local
671 or remote IPv4 (IPv6 is not supported by this option yet) address (or
672 range) before polling. Frequently \fIfetchmail\fP
673 is used over a transient point-to-point TCP/IP link established directly
674 to a mailserver via SLIP or PPP. That is a relatively secure channel.
675 But when other TCP/IP routes to the mailserver exist (e.g. when the link
676 is connected to an alternate ISP), your username and password may be
677 vulnerable to snooping (especially when daemon mode automatically polls
678 for mail, shipping a clear password over the net at predictable
679 intervals). The \-\-interface option may be used to prevent this. When
680 the specified link is not up or is not connected to a matching IP
681 address, polling will be skipped. The format is:
684 interface/iii.iii.iii.iii[/mmm.mmm.mmm.mmm]
687 The field before the first slash is the interface name (i.e. sl0, ppp0
688 etc.). The field before the second slash is the acceptable IP address.
689 The field after the second slash is a mask which specifies a range of
690 IP addresses to accept. If no mask is present 255.255.255.255 is
691 assumed (i.e. an exact match). This option is currently only supported
692 under Linux and FreeBSD. Please see the
694 section for below for FreeBSD specific information.
696 Note that this option may be removed from a future fetchmail version.
698 .B \-M <interface> | \-\-monitor <interface>
700 Daemon mode can cause transient links which are automatically taken down
701 after a period of inactivity (e.g. PPP links) to remain up
702 indefinitely. This option identifies a system TCP/IP interface to be
703 monitored for activity. After each poll interval, if the link is up but
704 no other activity has occurred on the link, then the poll will be
705 skipped. However, when fetchmail is woken up by a signal, the
706 monitor check is skipped and the poll goes through unconditionally.
707 This option is currently only supported under Linux and FreeBSD.
712 options to work for non root users under FreeBSD, the fetchmail binary
713 must be installed SGID kmem. This would be a security hole, but
714 fetchmail runs with the effective GID set to that of the kmem group
716 when interface data is being collected.
718 Note that this option may be removed from a future fetchmail version.
721 (Keyword: auth[enticate])
722 This option permits you to specify an authentication type (see USER
723 AUTHENTICATION below for details). The possible values are \fBany\fR,
724 \&\fBpassword\fR, \fBkerberos_v5\fR, \fBkerberos\fR (or, for
725 excruciating exactness, \fBkerberos_v4\fR), \fBgssapi\fR,
726 \fBcram\-md5\fR, \fBotp\fR, \fBntlm\fR, \fBmsn\fR (only for POP3) and
727 \fBssh\fR. When \fBany\fR (the default) is specified, fetchmail tries
728 first methods that don't require a password (GSSAPI, KERBEROS\ IV,
729 KERBEROS\ 5); then it looks for methods that mask your password
730 (CRAM-MD5, X\-OTP - note that NTLM and MSN are not autoprobed for POP3
731 and MSN is only supported for POP3); and only if the server doesn't
732 support any of those will it ship your password en clair. Other values
733 may be used to force various authentication methods
734 (\fBssh\fR suppresses authentication and is thus good for IMAP PREAUTH).
735 Any value other than \fBpassword\fR, \fBcram\-md5\fR, \fBntlm\fR,
736 \&\fBmsn\fR or \fBotp\fR suppresses fetchmail's normal inquiry for a
737 password. Specify \fBssh\fR when you are using an end-to-end secure
738 connection such as an ssh tunnel; specify \fBgssapi\fR or
739 \&\fBkerberos_v4\fR if you are using a protocol variant that employs
740 GSSAPI or K4. Choosing KPOP protocol automatically selects Kerberos
741 authentication. This option does not work with ETRN.
742 .SS Miscellaneous Options
744 .B \-f <pathname> | \-\-fetchmailrc <pathname>
745 Specify a non-default name for the
747 run control file. The pathname argument must be either "-" (a single
748 dash, meaning to read the configuration from standard input) or a
749 filename. Unless the \-\-version option is also on, a named file
750 argument must have permissions no more open than 0600 (u=rw,g=,o=) or
753 .B \-i <pathname> | \-\-idfile <pathname>
755 Specify an alternate name for the .fetchids file used to save POP3
756 UIDs. NOTE: since fetchmail 6.3.0, write access to the directory
757 containing the idfile is required, as fetchmail writes a temporary file
758 and renames it into the place of the real idfile only if the temporary
759 file has been written successfully. This avoids the truncation of
760 idfiles when running out of disk space.
762 .B \--pidfile <pathname>
763 (Keyword: pidfile; since fetchmail v6.3.4)
764 Override the default location of the PID file. Default: see
767 .B \-n | \-\-norewrite
768 (Keyword: no rewrite)
771 edits RFC-822 address headers (To, From, Cc, Bcc, and Reply\-To) in
772 fetched mail so that any mail IDs local to the server are expanded to
773 full addresses (@ and the mailserver hostname are appended). This enables
774 replies on the client to get addressed correctly (otherwise your
775 mailer might think they should be addressed to local users on the
776 client machine!). This option disables the rewrite. (This option is
777 provided to pacify people who are paranoid about having an MTA edit
778 mail headers and want to know they can prevent it, but it is generally
779 not a good idea to actually turn off rewrite.)
780 When using ETRN or ODMR, the rewrite option is ineffective.
782 .B \-E <line> | \-\-envelope <line>
783 (Keyword: envelope; Multidrop only)
785 In the configuration file, an enhanced syntax is used:
787 .B envelope [<count>] <line>
789 This option changes the header
791 assumes will carry a copy of the mail's envelope address. Normally
792 this is 'X\-Envelope\-To', but as this header is not standard, practice
793 varies. See the discussion of multidrop address handling below. As a
794 special case, 'envelope "Received"' enables parsing of sendmail-style
795 Received lines. This is the default, and it should not be necessary
796 unless you have globally disabled Received parsing with 'no envelope'
797 in the \fI.fetchmailrc\fR file.
799 The optional count argument (only available in the configuration file)
800 determines how many header lines of this kind are skipped. A count of 1
801 means: skip the first, take the second. A count of 2 means: skip the
802 first and second, take the third, and so on.
804 .B \-Q <prefix> | \-\-qvirtual <prefix>
805 (Keyword: qvirtual; Multidrop only)
806 The string prefix assigned to this option will be removed from the user
807 name found in the header specified with the \fIenvelope\fR option
808 (\fIbefore\fR doing multidrop name mapping or localdomain checking,
809 if either is applicable). This option is useful if you are using
811 to collect the mail for an entire domain and your ISP (or your mail
812 redirection provider) is using qmail.
813 One of the basic features of qmail is the
817 message header. Whenever qmail delivers a message to a local mailbox
818 it puts the username and hostname of the envelope recipient on this
819 line. The major reason for this is to prevent mail loops. To set up
820 qmail to batch mail for a disconnected site the ISP-mailhost will have
821 normally put that site in its 'Virtualhosts' control file so it will
822 add a prefix to all mail addresses for this site. This results in mail
823 .\" The \&@\& tries to stop HTML converters from making a mailto URL here.
824 sent to 'username\&@\&userhost.userdom.dom.com' having a
825 \&'Delivered\-To:' line of the form:
827 Delivered\-To: mbox\-userstr\-username\&@\&userhost.example.com
829 The ISP can make the 'mbox\-userstr\-' prefix anything they choose
830 but a string matching the user host name is likely.
831 By using the option 'envelope Delivered\-To:' you can make fetchmail reliably
832 identify the original envelope recipient, but you have to strip the
833 \&'mbox\-userstr\-' prefix to deliver to the correct user.
834 This is what this option is for.
839 file, interpret any command-line options specified, and dump a
840 configuration report to standard output. The configuration report is
841 a data structure assignment in the language Python. This option
842 is meant to be used with an interactive
850 Removed before version 6.3.0, the required underlying inet6_apps library
851 had been discontinued and is no longer available.
853 .SH USER AUTHENTICATION AND ENCRYPTION
854 All modes except ETRN require authentication of the client to the server.
855 Normal user authentication in
857 is very much like the authentication mechanism of
859 The correct user-id and password depend upon the underlying security
860 system at the mailserver.
862 If the mailserver is a Unix machine on which you have an ordinary user
863 account, your regular login name and password are used with
865 If you use the same login name on both the server and the client machines,
866 you needn't worry about specifying a user-id with the
868 option -- the default behavior is to use your login name on the
869 client machine as the user-id on the server machine. If you use a
870 different login name on the server machine, specify that login name
873 option. e.g. if your login name is 'jsmith' on a machine named 'mailgrunt',
878 fetchmail \-u jsmith mailgrunt
880 The default behavior of
882 is to prompt you for your mailserver password before the connection is
883 established. This is the safest way to use
885 and ensures that your password will not be compromised. You may also specify
886 your password in your
888 file. This is convenient when using
890 in daemon mode or with scripts.
891 .SS Using netrc files
893 If you do not specify a password, and
895 cannot extract one from your
897 file, it will look for a
899 file in your home directory before requesting one interactively; if an
900 entry matching the mailserver is found in that file, the password will
901 be used. Fetchmail first looks for a match on poll name; if it finds none,
902 it checks for a match on via name. See the
904 man page for details of the syntax of the
906 file. To show a practical example, a .netrc might look like
910 machine hermes.example.org
915 You can repeat this block with different user information if you need to
916 provide more than one password.
918 This feature may allow you to avoid duplicating password
919 information in more than one file.
921 On mailservers that do not provide ordinary user accounts, your user-id and
922 password are usually assigned by the server administrator when you apply for
923 a mailbox on the server. Contact your server administrator if you don't know
924 the correct user-id and password for your mailbox account.
927 Early versions of POP3 (RFC1081, RFC1225) supported a crude form of
928 independent authentication using the
930 file on the mailserver side. Under this RPOP variant, a fixed
931 per-user ID equivalent to a password was sent in clear over a link to
932 a reserved port, with the command RPOP rather than PASS to alert the
933 server that it should do special checking. RPOP is supported
936 (you can specify 'protocol RPOP' to have the program send 'RPOP'
937 rather than 'PASS') but its use is strongly discouraged, and support
938 will be removed from a future fetchmail version. This
939 facility was vulnerable to spoofing and was withdrawn in RFC1460.
941 RFC1460 introduced APOP authentication. In this variant of POP3,
942 you register an APOP password on your server host (the program
943 to do this with on the server is probably called \fIpopauth\fR(8)). You
944 put the same password in your
948 logs in, it sends a cryptographically secure hash of your password and
949 the server greeting time to the server, which can verify it by
950 checking its authorization database.
953 makes some efforts to make the server believe messages had not been
954 retrieved, by using the TOP command with a large number of lines when
955 possible. TOP is a command that retrieves the full header and
956 a \fIfetchmail\fP-specified amount of body lines. It is optional and
957 therefore not implemented by all servers, and some are known to
958 implement it improperly. On many servers however, the RETR command which
959 retrieves the full message with header and body, sets the "seen" flag
960 (for instance, in a web interface), whereas the TOP command does not do
964 will always use the RETR command if "fetchall" is set.
966 will also use the RETR command if "keep" is set and "uidl" is unset.
969 will use the RETR command on Maillennium POP3/PROXY
970 servers (used by Comcast) to avoid a deliberate TOP misinterpretation in
971 this server that causes message corruption.
975 will use the TOP command. This implies that in "keep" setups, "uidl"
976 must be set if "TOP" is desired.
979 that this description is true for the current version of fetchmail, but
980 the behavior may change in future versions. In particular, fetchmail may
981 prefer the RETR command because the TOP command causes much grief on
982 some servers and is only optional.
983 .SH ALTERNATE AUTHENTICATION FORMS
985 If your \fIfetchmail\fR was built with Kerberos support and you specify
986 Kerberos authentication (either with \-\-auth or the \fI.fetchmailrc\fR
987 option \fBauthenticate kerberos_v4\fR) it will try to get a Kerberos
988 ticket from the mailserver at the start of each query. Note: if
989 either the pollname or via name is 'hesiod', fetchmail will try to use
990 Hesiod to look up the mailserver.
992 If you use POP3 or IMAP with GSSAPI authentication, \fIfetchmail\fR will
993 expect the server to have RFC1731- or RFC1734-conforming GSSAPI
994 capability, and will use it. Currently this has only been tested over
995 Kerberos V, so you're expected to already have a ticket-granting
996 ticket. You may pass a username different from your principal name
997 using the standard \fB\-\-user\fR command or by the \fI.fetchmailrc\fR
1000 If your IMAP daemon returns the PREAUTH response in its greeting line,
1001 fetchmail will notice this and skip the normal authentication step.
1002 This can be useful, e.g. if you start imapd explicitly using ssh.
1003 In this case you can declare the authentication value 'ssh' on that
1004 site entry to stop \fI.fetchmail\fR from asking you for a password
1007 If you are using POP3, and the server issues a one-time-password
1008 challenge conforming to RFC1938, \fIfetchmail\fR will use your
1009 password as a pass phrase to generate the required response. This
1010 avoids sending secrets over the net unencrypted.
1012 Compuserve's RPA authentication (similar to APOP) is supported. If you
1013 compile in the support, \fIfetchmail\fR will try to perform an RPA pass-phrase
1014 authentication instead of sending over the password en clair if it
1015 detects "@compuserve.com" in the hostname.
1017 If you are using IMAP, Microsoft's NTLM authentication (used by Microsoft
1018 Exchange) is supported. If you compile in the support, \fIfetchmail\fR
1019 will try to perform an NTLM authentication (instead of sending over the
1020 password en clair) whenever the server returns AUTH=NTLM in its
1021 capability response. Specify a user option value that looks like
1022 \&'user@domain': the part to the left of the @ will be passed as the
1023 username and the part to the right as the NTLM domain.
1024 .SS Secure Socket Layers (SSL) and Transport Layer Security (TLS)
1026 You can access SSL encrypted services by specifying the \-\-ssl option.
1027 You can also do this using the "ssl" user option in the .fetchmailrc
1028 file. With SSL encryption enabled, queries are initiated over a connection
1029 after negotiating an SSL session. Some services, such as POP3 and IMAP,
1030 have different well known ports defined for the SSL encrypted services.
1031 The encrypted ports will be selected automatically when SSL is enabled and
1032 no explicit port is specified.
1034 When connecting to an SSL encrypted server, the server presents a certificate
1035 to the client for validation. The certificate is checked to verify that
1036 the common name in the certificate matches the name of the server being
1037 contacted and that the effective and expiration dates in the certificate
1038 indicate that it is currently valid. If any of these checks fail, a warning
1039 message is printed, but the connection continues. The server certificate
1040 does not need to be signed by any specific Certifying Authority and may
1041 be a "self-signed" certificate.
1043 Some SSL encrypted servers may request a client side certificate. A client
1044 side public SSL certificate and private SSL key may be specified. If
1045 requested by the server, the client certificate is sent to the server for
1046 validation. Some servers may require a valid client certificate and may
1047 refuse connections if a certificate is not provided or if the certificate
1048 is not valid. Some servers may require client side certificates be signed
1049 by a recognized Certifying Authority. The format for the key files and
1050 the certificate files is that required by the underlying SSL libraries
1051 (OpenSSL in the general case).
1053 A word of care about the use of SSL: While above mentioned
1054 setup with self-signed server certificates retrieved over the wires
1055 can protect you from a passive eavesdropper it doesn't help against an
1056 active attacker. It's clearly an improvement over sending the
1057 passwords in clear but you should be aware that a man-in-the-middle
1058 attack is trivially possible (in particular with tools such as dsniff,
1059 http://monkey.org/~dugsong/dsniff/). Use of an ssh tunnel (see
1060 below for some examples) is preferable if you care seriously about the
1061 security of your mailbox.
1065 also supports authentication to the ESMTP server on the client side
1066 according to RFC 2554. You can specify a name/password pair to be
1067 used with the keywords 'esmtpname' and 'esmtppassword'; the former
1068 defaults to the username of the calling user.
1072 .B \-\-daemon <interval>
1077 in daemon mode. You must specify a numeric argument which is a
1078 polling interval in seconds.
1082 puts itself in background and runs forever, querying each specified
1083 host and then sleeping for the given polling interval.
1089 will, therefore, poll all the hosts described in your
1091 file (except those explicitly excluded with the 'skip' verb) once
1092 every fifteen minutes.
1094 It is possible to set a polling interval
1097 file by saying 'set daemon <interval>', where <interval> is an
1098 integer number of seconds. If you do this, fetchmail will always
1099 start in daemon mode unless you override it with the command-line
1100 option \-\-daemon 0 or \-d0.
1102 Only one daemon process is permitted per user; in daemon mode,
1104 makes a per-user lockfile to guarantee this.
1106 Normally, calling fetchmail with a daemon in the background sends a
1107 wake-up signal to the daemon, forcing it to poll mailservers
1108 immediately. (The wake-up signal is SIGHUP if fetchmail is running as
1109 root, SIGUSR1 otherwise.) The wake-up action also clears any 'wedged'
1110 flags indicating that connections have wedged due to failed
1111 authentication or multiple timeouts.
1115 will kill a running daemon process instead of waking it up (if there
1116 is no such process, \fIfetchmail\fP will notify you.
1117 If the \-\-quit option appears last on the command line, \fIfetchmail\fP
1118 will kill the running daemon process and then quit. Otherwise,
1119 \fIfetchmail\fP will first kill a running daemon process and then
1120 continue running with the other options.
1125 .B \-\-logfile <filename>
1126 option (keyword: set logfile) is only effective when fetchmail is
1127 detached. This option allows you to redirect status messages
1128 into a specified logfile (follow the option with the logfile name). The
1129 logfile is opened for append, so previous messages aren't deleted. This
1130 is primarily useful for debugging configurations.
1134 option (keyword: set syslog) allows you to redirect status and error
1135 messages emitted to the
1137 system daemon if available.
1138 Messages are logged with an id of \fBfetchmail\fR, the facility \fBLOG_MAIL\fR,
1139 and priorities \fBLOG_ERR\fR, \fBLOG_ALERT\fR or \fBLOG_INFO\fR.
1140 This option is intended for logging status and error messages which
1141 indicate the status of the daemon and the results while fetching mail
1143 Error messages for command line options and parsing the \fI.fetchmailrc\fR
1144 file are still written to stderr, or to the specified log file.
1147 option turns off use of
1149 assuming it's turned on in the
1154 .B \-\-logfile <file>
1161 option suppresses backgrounding and detachment of the
1162 daemon process from its control terminal. This is useful
1163 for debugging or when fetchmail runs as the child of a supervisor
1168 Note that this also causes the logfile option to be
1169 ignored (though perhaps it shouldn't).
1171 Note that while running in daemon mode polling a POP2 or IMAP2bis server,
1172 transient errors (such as DNS failures or sendmail delivery refusals)
1173 may force the fetchall option on for the duration of the next polling
1174 cycle. This is a robustness feature. It means that if a message is
1175 fetched (and thus marked seen by the mailserver) but not delivered
1176 locally due to some transient error, it will be re-fetched during the
1177 next poll cycle. (The IMAP logic doesn't delete messages until
1178 they're delivered, so this problem does not arise.)
1180 If you touch or change the
1182 file while fetchmail is running in daemon mode, this will be detected
1183 at the beginning of the next poll cycle. When a changed
1185 is detected, fetchmail rereads it and restarts from scratch (using
1186 exec(2); no state information is retained in the new instance). Note also
1187 that if you break the
1189 file's syntax, the new instance will softly and silently vanish away
1192 .SH ADMINISTRATIVE OPTIONS
1195 .B \-\-postmaster <name>
1196 option (keyword: set postmaster) specifies the last-resort username to
1197 which multidrop mail is to be forwarded if no matching local recipient
1198 can be found. It is also used as destination of undeliverable mail if
1199 the 'bouncemail' global option is off and additionally for spam-blocked
1200 mail if the 'bouncemail' global option is off and the 'spambounce'
1201 global option is on. This option defaults to the user who invoked
1203 If the invoking user is root, then the default of this option is
1204 the user 'postmaster'. Setting postmaster to the empty string causes
1205 such mail as described above to be discarded - this however is usually a
1207 See also the description of the 'FETCHMAILUSER' environment variable in
1208 the ENVIRONMENT section below.
1212 behaves like the "set no bouncemail" global option, which see.
1216 option (keyword: set invisible) tries to make fetchmail invisible.
1217 Normally, fetchmail behaves like any other MTA would -- it generates a
1218 Received header into each message describing its place in the chain of
1219 transmission, and tells the MTA it forwards to that the mail came from
1220 the machine fetchmail itself is running on. If the invisible option
1221 is on, the Received header is suppressed and fetchmail tries to spoof
1222 the MTA it forwards to into thinking it came directly from the
1227 option (keyword: set showdots) forces fetchmail to show progress dots
1228 even if the current tty is not stdout (for example logfiles).
1229 Fetchmail shows the dots by default when run in nodetach mode or when
1230 daemon mode is not enabled.
1234 option, you can ask fetchmail to add information to the Received
1235 header on the form "polling {label} account {user}", where {label} is
1236 the account label (from the specified rcfile, normally ~/.fetchmailrc)
1237 and {user} is the username which is used to log on to the mail
1238 server. This header can be used to make filtering email where no
1239 useful header information is available and you want mail from
1240 different accounts sorted into different mailboxes (this could, for
1241 example, occur if you have an account on the same server running a
1242 mailing list, and are subscribed to the list using that account). The
1243 default is not adding any such header. In
1245 this is called 'tracepolls'.
1247 .SH RETRIEVAL FAILURE MODES
1248 The protocols \fIfetchmail\fR uses to talk to mailservers are next to
1249 bulletproof. In normal operation forwarding to port 25, no message is
1250 ever deleted (or even marked for deletion) on the host until the SMTP
1251 listener on the client side has acknowledged to \fIfetchmail\fR that
1252 the message has been either accepted for delivery or rejected due to a
1255 When forwarding to an MDA, however, there is more possibility
1256 of error. Some MDAs are 'safe' and reliably return a nonzero status
1257 on any delivery error, even one due to temporary resource limits.
1260 program is like this; so are most programs designed as mail transport
1263 including the sendmail wrapper of Postfix and
1265 These programs give back a reliable positive acknowledgement and
1266 can be used with the mda option with no risk of mail loss. Unsafe
1267 MDAs, though, may return 0 even on delivery failure. If this
1268 happens, you will lose mail.
1270 The normal mode of \fIfetchmail\fR is to try to download only 'new'
1271 messages, leaving untouched (and undeleted) messages you have already
1272 read directly on the server (or fetched with a previous \fIfetchmail
1273 --keep\fR). But you may find that messages you've already read on the
1274 server are being fetched (and deleted) even when you don't specify
1275 --all. There are several reasons this can happen.
1277 One could be that you're using POP2. The POP2 protocol includes no
1278 representation of 'new' or 'old' state in messages, so \fIfetchmail\fR
1279 must treat all messages as new all the time. But POP2 is obsolete, so
1282 A potential POP3 problem might be servers that insert messages
1283 in the middle of mailboxes (some VMS implementations of mail are
1284 rumored to do this). The \fIfetchmail\fR code assumes that new
1285 messages are appended to the end of the mailbox; when this is not true
1286 it may treat some old messages as new and vice versa. Using UIDL whilst
1287 setting fastuidl 0 might fix this, otherwise, consider switching to IMAP.
1289 Yet another POP3 problem is that if they can't make tempfiles in the
1290 user's home directory, some POP3 servers will hand back an
1291 undocumented response that causes fetchmail to spuriously report "No
1294 The IMAP code uses the presence or absence of the server flag \eSeen
1295 to decide whether or not a message is new. This isn't the right thing
1296 to do, fetchmail should check the UIDVALIDITY and use UID, but it
1297 doesn't do that yet. Under Unix, it counts on your IMAP server to notice
1298 the BSD-style Status flags set by mail user agents and set the \eSeen
1299 flag from them when appropriate. All Unix IMAP servers we know of do
1300 this, though it's not specified by the IMAP RFCs. If you ever trip over
1301 a server that doesn't, the symptom will be that messages you have
1302 already read on your host will look new to the server. In this
1303 (unlikely) case, only messages you fetched with \fIfetchmail \-\-keep\fR
1304 will be both undeleted and marked old.
1306 In ETRN and ODMR modes, \fIfetchmail\fR does not actually retrieve messages;
1307 instead, it asks the server's SMTP listener to start a queue flush
1308 to the client via SMTP. Therefore it sends only undelivered messages.
1311 Many SMTP listeners allow administrators to set up 'spam filters' that
1312 block unsolicited email from specified domains. A MAIL FROM or DATA line that
1313 triggers this feature will elicit an SMTP response which
1314 (unfortunately) varies according to the listener.
1318 return an error code of 571.
1320 According to RFC2821, the correct thing to return in this situation is
1321 550 "Requested action not taken: mailbox unavailable" (the draft adds
1322 "[E.g., mailbox not found, no access, or command rejected for policy
1325 Older versions of the
1327 MTA return 501 "Syntax error in parameters or arguments".
1331 MTA runs 554 as an antispam response.
1334 may reject code with a 500 response (followed by an enhanced status
1335 code that contains more information).
1339 treats as antispam responses and discards
1340 the message can be set with the 'antispam' option. This is one of the
1342 three circumstance under which fetchmail ever discards mail (the others
1343 are the 552 and 553 errors described below, and the suppression of
1344 multidropped messages with a message-ID already seen).
1348 is fetching from an IMAP server, the antispam response will be detected and
1349 the message rejected immediately after the headers have been fetched,
1350 without reading the message body. Thus, you won't pay for downloading
1351 spam message bodies.
1353 By default, the list of antispam responses is empty.
1355 If the \fIspambounce\fR global option is on, mail that is spam-blocked
1356 triggers an RFC1892/RFC1894 bounce message informing the originator that
1357 we do not accept mail from it. See also BUGS.
1359 .SH SMTP/ESMTP ERROR HANDLING
1360 Besides the spam-blocking described above, fetchmail takes special
1361 actions on the following SMTP/ESMTP error responses
1363 452 (insufficient system storage)
1364 Leave the message in the server mailbox for later retrieval.
1366 552 (message exceeds fixed maximum message size)
1367 Delete the message from the server. Send bounce-mail to the
1370 553 (invalid sending domain)
1371 Delete the message from the server. Don't even try to send
1372 bounce-mail to the originator.
1374 Other errors trigger bounce mail back to the originator. See also BUGS.
1376 .SH THE RUN CONTROL FILE
1377 The preferred way to set up fetchmail is to write a
1378 \&\fI.fetchmailrc\fR file in your home directory (you may do this
1379 directly, with a text editor, or indirectly via \fIfetchmailconf\fR).
1380 When there is a conflict between the command-line arguments and the
1381 arguments in this file, the command-line arguments take precedence.
1383 To protect the security of your passwords,
1384 your \fI~/.fetchmailrc\fR may not normally have more than 0600 (u=rw,g=,o=) permissions;
1386 will complain and exit otherwise (this check is suppressed when
1389 You may read the \fI.fetchmailrc\fR file as a list of commands to
1392 is called with no arguments.
1393 .SS Run Control Syntax
1395 Comments begin with a '#' and extend through the end of the line.
1396 Otherwise the file consists of a series of server entries or global
1397 option statements in a free-format, token-oriented syntax.
1399 There are four kinds of tokens: grammar keywords, numbers
1400 (i.e. decimal digit sequences), unquoted strings, and quoted strings.
1401 A quoted string is bounded by double quotes and may contain
1402 whitespace (and quoted digits are treated as a string). Note that
1403 quoted strings will also contain line feed characters if they run across
1404 two or more lines, unless you use a backslash to join lines (see below).
1405 An unquoted string is any whitespace-delimited token that is neither
1406 numeric, string quoted nor contains the special characters ',', ';',
1409 Any amount of whitespace separates tokens in server entries, but is
1410 otherwise ignored. You may use backslash escape sequences (\en for LF,
1411 \&\et for HT, \eb for BS, \er for CR, \e\fInnn\fP for decimal (where
1412 nnn cannot start with a 0), \e0\fIooo\fP for octal, and \ex\fIhh\fP for
1413 hex) to embed non-printable characters or string delimiters in strings.
1414 In quoted strings, a backslash at the very end of a line will cause the
1415 backslash itself and the line feed (LF or NL, new line) character to be
1416 ignored, so that you can wrap long strings. Without the backslash at the
1417 line end, the line feed character would become part of the string.
1420 while these resemble C-style escape sequences, they are not the same.
1421 fetchmail only supports these eight styles. C supports more escape
1422 sequences that consist of backslash (\e) and a single character, but
1423 does not support decimal codes and does not require the leading 0 in
1424 octal notation. Example: fetchmail interprets \e233 the same as \exE9
1425 (Latin small letter e with acute), where C would interpret \e233 as
1426 octal 0233 = \ex9B (CSI, control sequence introducer).
1428 Each server entry consists of one of the keywords 'poll' or 'skip',
1429 followed by a server name, followed by server options, followed by any
1430 number of user descriptions. Note: the most common cause of syntax
1431 errors is mixing up user and server options.
1433 For backward compatibility, the word 'server' is a synonym for 'poll'.
1435 You can use the noise keywords 'and', 'with',
1436 \&'has', 'wants', and 'options' anywhere in an entry to make
1437 it resemble English. They're ignored, but but can make entries much
1438 easier to read at a glance. The punctuation characters ':', ';' and
1439 \&',' are also ignored.
1442 The 'poll' verb tells fetchmail to query this host when it is run with
1443 no arguments. The 'skip' verb tells
1445 not to poll this host unless it is explicitly named on the command
1446 line. (The 'skip' verb allows you to experiment with test entries
1447 safely, or easily disable entries for hosts that are temporarily down.)
1449 .SS Keyword/Option Summary
1450 Here are the legal options. Keyword suffixes enclosed in
1451 square brackets are optional. Those corresponding to short command-line
1452 options are followed by '\-' and the appropriate option letter. If
1453 option is only relevant to a single mode of operation, it is noted as
1454 \&'s' or 'm' for singledrop- or multidrop-mode, respectively.
1456 Here are the legal global options:
1460 Keyword Opt Mode Function
1462 set daemon \-d \& T{
1463 Set a background poll interval in seconds.
1465 set postmaster \& \& T{
1466 Give the name of the last-resort mail recipient (default: user running
1467 fetchmail, "postmaster" if run by the root user)
1469 set bouncemail \& \& T{
1470 Direct error mail to the sender (default)
1472 set no bouncemail \& \& T{
1473 Direct error mail to the local postmaster (as per the 'postmaster'
1474 global option above).
1476 set no spambounce \& \& T{
1477 Do not bounce spam-blocked mail (default).
1479 set spambounce \& \& T{
1480 Bounce blocked spam-blocked mail (as per the 'antispam' user option)
1481 back to the destination as indicated by the 'bouncemail' global option.
1482 Warning: Do not use this to bounce spam back to the sender - most spam
1483 is sent with false sender address and thus this option hurts innocent
1486 set logfile \-L \& T{
1487 Name of a file to append error and status messages to.
1489 set idfile \-i \& T{
1490 Name of the file to store UID lists in.
1493 Do error logging through syslog(3).
1495 set no syslog \& \& T{
1496 Turn off error logging through syslog(3). (default)
1498 set properties \& \& T{
1499 String value that is ignored by fetchmail (may be used by extension
1504 Here are the legal server options:
1508 Keyword Opt Mode Function
1511 Specify DNS name of mailserver, overriding poll name
1513 proto[col] \-p \& T{
1514 Specify protocol (case insensitive):
1515 POP2, POP3, IMAP, APOP, KPOP
1517 local[domains] \& m T{
1518 Specify domain(s) to be regarded as local
1521 Specify TCP/IP service port (obsolete, use 'service' instead).
1524 Specify service name (a numeric value is also allowed and
1525 considered a TCP/IP port number).
1527 auth[enticate] \& \& T{
1528 Set authentication type (default 'any')
1531 Server inactivity timeout in seconds (default 300)
1534 Specify envelope-address header name
1537 Disable looking for envelope address
1540 Qmail virtual domain prefix to remove from user name
1543 Specify alternate DNS names of mailserver
1546 specify IP interface(s) that must be up for server poll to take place
1549 Specify IP address to monitor for activity
1552 Specify command through which to make server connections.
1555 Specify command through which to make listener connections.
1558 Enable DNS lookup for multidrop (default)
1561 Disable DNS lookup for multidrop
1564 Do comparison by IP address for multidrop
1566 no checkalias \& m T{
1567 Do comparison by name for multidrop (default)
1570 Force POP3 to use client-side UIDLs (recommended)
1573 Turn off POP3 use of client-side UIDLs (default)
1576 Only check this site every N poll cycles; N is a numeric argument.
1579 Add poll tracing information to the Received header
1582 Set Kerberos principal (only useful with imap and kerberos)
1585 Set name for RFC2554 authentication to the ESMTP server.
1587 esmtppassword \& \& T{
1588 Set password for RFC2554 authentication to the ESMTP server.
1592 Here are the legal user options:
1596 Keyword Opt Mode Function
1598 user[name] \-u \& T{
1599 Set remote user name
1600 (local user name if name followed by 'here')
1603 Connect local and remote user names
1606 Connect local and remote user names
1609 Specify remote account password
1612 Connect to server over the specified base protocol using SSL encryption
1615 Specify file for client side public SSL certificate
1618 Specify file for client side private SSL key
1621 Force ssl protocol for connection
1624 Specify remote folder to query
1627 Specify smtp host(s) to forward to
1629 fetchdomains \& m T{
1630 Specify domains for which mail should be fetched
1632 smtpaddress \-D \& T{
1633 Specify the domain to be put in RCPT TO lines
1636 Specify the user and domain to be put in RCPT TO lines
1639 Specify what SMTP returns are interpreted as spam-policy blocks
1642 Specify MDA for local delivery
1645 Specify BSMTP batch file to append to
1648 Command to be executed before each connection
1650 postconnect \& \& T{
1651 Command to be executed after each connection
1654 Don't delete seen messages from server
1657 Flush all seen messages before querying (DANGEROUS)
1660 Flush all oversized messages before querying
1663 Fetch all messages whether seen or not
1666 Rewrite destination addresses for reply (default)
1669 Strip carriage returns from ends of lines
1672 Force carriage returns at ends of lines
1675 Force BODY=8BITMIME to ESMTP listener
1678 Strip Status and X-Mozilla-Status lines out of incoming mail
1680 dropdelivered \& \& T{
1681 Strip Delivered-To lines out of incoming mail
1684 Convert quoted-printable to 8-bit in MIME messages
1687 Idle waiting for new messages after each poll (IMAP only)
1690 Delete seen messages from server (default)
1693 Don't flush all seen messages before querying (default)
1695 no fetchall \& \& T{
1696 Retrieve only new messages (default)
1699 Don't rewrite headers
1702 Don't strip carriage returns (default)
1705 Don't force carriage returns at EOL (default)
1707 no pass8bits \& \& T{
1708 Don't force BODY=8BITMIME to ESMTP listener (default)
1710 no dropstatus \& \& T{
1711 Don't drop Status headers (default)
1713 no dropdelivered \& \& T{
1714 Don't drop Delivered\-To headers (default)
1716 no mimedecode \& \& T{
1717 Don't convert quoted-printable to 8-bit in MIME messages (default)
1720 Don't idle waiting for new messages after each poll (IMAP only)
1723 Set message size limit
1726 Set message size warning interval
1728 batchlimit \-b \& T{
1729 Max # messages to forward in single connect
1731 fetchlimit \-B \& T{
1732 Max # messages to fetch in single connect
1734 fetchsizelimit \& \& T{
1735 Max # message sizes to fetch in single transaction
1738 Use binary search for first unseen message (POP3 only)
1741 Perform an expunge on every #th message (IMAP and POP3 only)
1744 String value is ignored by fetchmail (may be used by extension scripts)
1748 Remember that all user options must \fIfollow\fR all server options.
1750 In the .fetchmailrc file, the 'envelope' string argument may be
1751 preceded by a whitespace-separated number. This number, if specified,
1752 is the number of such headers to skip over (that is, an argument of 1
1753 selects the second header of the given type). This is sometime useful
1754 for ignoring bogus envelope headers created by an ISP's local delivery
1755 agent or internal forwards (through mail inspection systems, for
1757 .SS Keywords Not Corresponding To Option Switches
1759 The 'folder' and 'smtphost' options (unlike their command-line
1760 equivalents) can take a space- or comma-separated list of names
1763 All options correspond to the obvious command-line arguments, except
1764 the following: 'via', 'interval', 'aka', 'is', 'to', 'dns'/'no dns',
1765 \&'checkalias'/'no checkalias', 'password', 'preconnect', 'postconnect',
1766 \&'localdomains', 'stripcr'/'no stripcr', 'forcecr'/'no forcecr',
1767 \&'pass8bits'/'no pass8bits' 'dropstatus/no dropstatus',
1768 \&'dropdelivered/no dropdelivered', 'mimedecode/no mimedecode', 'no idle',
1771 The 'via' option is for if you want to have more
1772 than one configuration pointing at the same site. If it is present,
1773 the string argument will be taken as the actual DNS name of the
1774 mailserver host to query.
1775 This will override the argument of poll, which can then simply be a
1776 distinct label for the configuration (e.g. what you would give on the
1777 command line to explicitly query this host).
1779 The 'interval' option (which takes a numeric argument) allows you to poll a
1780 server less frequently than the basic poll interval. If you say
1781 \&'interval N' the server this option is attached to will only be
1782 queried every N poll intervals.
1784 The 'is' or 'to' keywords associate the following local (client)
1785 name(s) (or server-name to client-name mappings separated by =) with
1786 the mailserver user name in the entry. If an is/to list has '*' as
1787 its last name, unrecognized names are simply passed through.
1789 A single local name can be used to support redirecting your mail when
1790 your username on the client machine is different from your name on the
1791 mailserver. When there is only a single local name, mail is forwarded
1792 to that local username regardless of the message's Received, To, Cc,
1793 and Bcc headers. In this case
1795 never does DNS lookups.
1797 When there is more than one local name (or name mapping) the
1798 \fIfetchmail\fR code does look at the Received, To, Cc, and Bcc
1799 headers of retrieved mail (this is 'multidrop mode'). It looks for
1800 addresses with hostname parts that match your poll name or your 'via',
1801 \&'aka' or 'localdomains' options, and usually also for hostname parts
1802 which DNS tells it are aliases of the mailserver. See the discussion
1803 of 'dns', 'checkalias', 'localdomains', and 'aka' for details on how
1804 matching addresses are handled.
1806 If \fIfetchmail\fR cannot match any mailserver usernames or
1807 localdomain addresses, the mail will be bounced.
1808 Normally it will be bounced to the sender, but if the 'bouncemail'
1809 global option is off, the mail will go to the local postmaster instead.
1810 (see the 'postmaster' global option). See also BUGS.
1812 The 'dns' option (normally on) controls the way addresses from
1813 multidrop mailboxes are checked. On, it enables logic to check each
1814 host address that does not match an 'aka' or 'localdomains' declaration
1815 by looking it up with DNS. When a mailserver username is recognized
1816 attached to a matching hostname part, its local mapping is added to
1817 the list of local recipients.
1819 The 'checkalias' option (normally off) extends the lookups performed
1820 by the 'dns' keyword in multidrop mode, providing a way to cope with
1821 remote MTAs that identify themselves using their canonical name, while
1822 they're polled using an alias.
1823 When such a server is polled, checks to extract the envelope address
1826 reverts to delivery using the To/Cc/Bcc headers (See below
1827 \&'Header vs. Envelope addresses').
1828 Specifying this option instructs
1830 to retrieve all the IP addresses associated with both the poll name
1831 and the name used by the remote MTA and to do a comparison of the IP
1832 addresses. This comes in handy in situations where the remote server
1833 undergoes frequent canonical name changes, that would otherwise
1834 require modifications to the rcfile. 'checkalias' has no effect if
1835 \&'no dns' is specified in the rcfile.
1837 The 'aka' option is for use with multidrop mailboxes. It allows you
1838 to pre-declare a list of DNS aliases for a server. This is an
1839 optimization hack that allows you to trade space for speed. When
1841 while processing a multidrop mailbox, grovels through message headers
1842 looking for names of the mailserver, pre-declaring common ones can
1843 save it from having to do DNS lookups. Note: the names you give
1844 as arguments to 'aka' are matched as suffixes -- if you specify
1845 (say) 'aka netaxs.com', this will match not just a hostname
1846 netaxs.com, but any hostname that ends with '.netaxs.com'; such as
1847 (say) pop3.netaxs.com and mail.netaxs.com.
1849 The 'localdomains' option allows you to declare a list of domains
1850 which fetchmail should consider local. When fetchmail is parsing
1851 address lines in multidrop modes, and a trailing segment of a host
1852 name matches a declared local domain, that address is passed through
1853 to the listener or MDA unaltered (local-name mappings are \fInot\fR
1856 If you are using 'localdomains', you may also need to specify 'no
1857 envelope', which disables \fIfetchmail\fR's normal attempt to deduce
1858 an envelope address from the Received line or X-Envelope-To header or
1859 whatever header has been previously set by 'envelope'. If you set 'no
1860 envelope' in the defaults entry it is possible to undo that in
1861 individual entries by using 'envelope <string>'. As a special case,
1862 \&'envelope "Received"' restores the default parsing of
1865 The \fBpassword\fR option requires a string argument, which is the password
1866 to be used with the entry's server.
1868 The 'preconnect' keyword allows you to specify a shell command to be
1869 executed just before each time
1871 establishes a mailserver connection. This may be useful if you are
1872 attempting to set up secure POP connections with the aid of
1874 If the command returns a nonzero status, the poll of that mailserver
1877 Similarly, the 'postconnect' keyword similarly allows you to specify a
1878 shell command to be executed just after each time a mailserver
1879 connection is taken down.
1881 The 'forcecr' option controls whether lines terminated by LF only are
1882 given CRLF termination before forwarding. Strictly speaking RFC821
1883 requires this, but few MTAs enforce the requirement it so this option
1884 is normally off (only one such MTA, qmail, is in significant use at
1887 The 'stripcr' option controls whether carriage returns are stripped
1888 out of retrieved mail before it is forwarded. It is normally not
1889 necessary to set this, because it defaults to 'on' (CR stripping
1890 enabled) when there is an MDA declared but 'off' (CR stripping
1891 disabled) when forwarding is via SMTP. If 'stripcr' and 'forcecr' are
1892 both on, 'stripcr' will override.
1894 The 'pass8bits' option exists to cope with Microsoft mail programs that
1895 stupidly slap a "Content-Transfer-Encoding: 7bit" on everything. With
1896 this option off (the default) and such a header present,
1898 declares BODY=7BIT to an ESMTP-capable listener; this causes problems for
1899 messages actually using 8-bit ISO or KOI-8 character sets, which will
1900 be garbled by having the high bits of all characters stripped. If
1901 \&'pass8bits' is on,
1903 is forced to declare BODY=8BITMIME to any ESMTP-capable listener. If
1904 the listener is 8-bit-clean (as all the major ones now are) the right
1905 thing will probably result.
1907 The 'dropstatus' option controls whether nonempty Status and
1908 X-Mozilla-Status lines are retained in fetched mail (the default) or
1909 discarded. Retaining them allows your MUA to see what messages (if
1910 any) were marked seen on the server. On the other hand, it can
1911 confuse some new-mail notifiers, which assume that anything with a
1912 Status line in it has been seen. (Note: the empty Status lines
1913 inserted by some buggy POP servers are unconditionally discarded.)
1915 The 'dropdelivered' option controls whether Delivered\-To headers will
1916 be kept in fetched mail (the default) or discarded. These headers are
1917 added by Qmail and Postfix mailservers in order to avoid mail loops but
1918 may get in your way if you try to "mirror" a mailserver within the same
1919 domain. Use with caution.
1921 The 'mimedecode' option controls whether MIME messages using the
1922 quoted-printable encoding are automatically converted into pure 8-bit
1923 data. If you are delivering mail to an ESMTP-capable, 8-bit-clean
1924 listener (that includes all of the major MTAs like sendmail), then
1925 this will automatically convert quoted-printable message headers and
1926 data into 8-bit data, making it easier to understand when reading
1927 mail. If your e-mail programs know how to deal with MIME messages,
1928 then this option is not needed. The mimedecode option is off by
1929 default, because doing RFC2047 conversion on headers throws away
1930 character-set information and can lead to bad results if the encoding
1931 of the headers differs from the body encoding.
1933 The 'idle' option is intended to be used with IMAP servers supporting
1934 the RFC2177 IDLE command extension, but does not strictly require it.
1935 If it is enabled, and fetchmail detects that IDLE is supported, an
1936 IDLE will be issued at the end of each poll. This will tell the IMAP
1937 server to hold the connection open and notify the client when new mail
1938 is available. If IDLE is not supported, fetchmail will simulate it by
1939 periodically issuing NOOP. If you need to poll a link frequently, IDLE
1940 can save bandwidth by eliminating TCP/IP connects and LOGIN/LOGOUT
1941 sequences. On the other hand, an IDLE connection will eat almost all
1942 of your fetchmail's time, because it will never drop the connection
1943 and allow other polls to occur unless the server times out the IDLE.
1944 It also doesn't work with multiple folders; only the first folder will
1948 The 'properties' option is an extension mechanism. It takes a string
1949 argument, which is ignored by fetchmail itself. The string argument may be
1950 used to store configuration information for scripts which require it.
1951 In particular, the output of '\-\-configdump' option will make properties
1952 associated with a user entry readily available to a Python script.
1954 .SS Miscellaneous Run Control Options
1955 The words 'here' and 'there' have useful English-like
1956 significance. Normally 'user eric is esr' would mean that
1957 mail for the remote user 'eric' is to be delivered to 'esr',
1958 but you can make this clearer by saying 'user eric there is esr here',
1959 or reverse it by saying 'user esr here is eric there'
1961 Legal protocol identifiers for use with the 'protocol' keyword are:
1964 auto (or AUTO) (legacy, to be removed from future release)
1965 pop2 (or POP2) (legacy, to be removed from future release)
1974 Legal authentication types are 'any', 'password', 'kerberos',
1975 \&'kerberos_v4', 'kerberos_v5' and 'gssapi', 'cram\-md5', 'otp', 'msn'
1976 (only for POP3), 'ntlm', 'ssh'. The 'password' type specifies
1977 authentication by normal transmission of a password (the password may be
1978 plain text or subject to protocol-specific encryption as in APOP);
1979 \&'kerberos' tells \fIfetchmail\fR to try to get a Kerberos ticket at the
1980 start of each query instead, and send an arbitrary string as the
1981 password; and 'gssapi' tells fetchmail to use GSSAPI authentication.
1982 See the description of the 'auth' keyword for more.
1984 Specifying 'kpop' sets POP3 protocol over port 1109 with Kerberos V4
1985 authentication. These defaults may be overridden by later options.
1987 There are some global option statements: 'set logfile'
1988 followed by a string sets the same global specified by \-\-logfile. A
1989 command-line \-\-logfile option will override this. Note that \-\-logfile is
1990 only effective if fetchmail detaches itself from the terminal. Also,
1991 \&'set daemon' sets the poll interval as \-\-daemon does. This can be
1992 overridden by a command-line \-\-daemon option; in particular \-\-daemon\~0
1993 can be used to force foreground operation. The 'set postmaster'
1994 statement sets the address to which multidrop mail defaults if there are
1995 no local matches. Finally, 'set syslog' sends log messages to
1998 .SH DEBUGGING FETCHMAIL
1999 .SS Fetchmail crashing
2000 There are various ways in that fetchmail may "crash", i. e. stop
2001 operation suddenly and unexpectedly. A "crash" usually refers to an
2002 error condition that the software did not handle by itself. A well-known
2003 failure mode is the "segmentation fault" or "signal 11" or "SIGSEGV" or
2004 just "segfault" for short. These can be caused by hardware or by software
2005 problems. Software-induced segfaults can usually be reproduced easily
2006 and in the same place, whereas hardware-induced segfaults can go away if
2007 the computer is rebooted, or powered off for a few hours, and can happen
2008 in random locations even if you use the software the same way.
2010 For solving hardware-induced segfaults, find the faulty component and repair or
2011 replace it. <http://www.bitwizard.nl/sig11/> may help you with details.
2013 For solving software-induced segfaults, the developers may need a "stack
2016 .SS Enabling fetchmail core dumps
2017 By default, fetchmail suppresses core dumps as these might contain
2018 passwords and other sensitive information. For debugging fetchmail
2019 crashes, obtaining a "stack backtrace" from a core dump is often the
2020 quickest way to solve the problem, and when posting your problem on a
2021 mailing list, the developers may ask you for a "backtrace".
2023 1. To get useful backtraces, fetchmail needs to be installed without
2024 getting stripped of its compilation symbols. Unfortunately, most
2025 binary packages that are installed are stripped, and core files from
2026 symbol-stripped programs are worthless. So you may need to recompile
2027 fetchmail. On many systems, you can type
2030 file `which fetchmail`
2033 to find out if fetchmail was symbol-stripped or not. If yours was
2034 unstripped, fine, proceed, if it was stripped, you need to recompile the
2035 source code first. You do not usually need to install fetchmail in order
2038 2. The shell environment that starts fetchmail needs to enable core
2039 dumps. The key is the "maximum core (file) size" that can usually be
2040 configured with a tool named "limit" or "ulimit". See the documentation
2041 for your shell for details. In the popular bash shell, "ulimit \-Sc
2042 unlimited" will allow the core dump.
2044 3. You need to tell fetchmail, too, to allow core dumps. To do
2045 this, run fetchmail with the \fB\-d0 \-v\fP options. It is often easier
2046 to also add \fB\-\-nosyslog \-N\fR as well.
2048 Finally, you need to reproduce the crash. You can just start fetchmail
2049 from the directory where you compiled it by typing \fB./fetchmail\fR,
2050 so the complete command line will start with \fB./fetchmail \-Nvd0
2051 \&\-\-nosyslog\fR and perhaps list your other options.
2053 After the crash, run your debugger to obtain the core dump. The
2054 debugger will often be GNU GDB, you can then type (adjust paths as
2055 necessary) \fBgdb ./fetchmail fetchmail.core\fR and then, after GDB
2056 has started up and read all its files, type \fBbacktrace full\fR, save
2057 the output (copy & paste will do, the backtrace will be read by a human)
2058 and then type \fBquit\fR to leave gdb.
2060 on some systems, the core
2061 files have different names, they might contain a number instead of the
2062 program name, or number and name, but it will usually have "core" as
2065 .SH INTERACTION WITH RFC 822
2066 When trying to determine the originating address of a message,
2067 fetchmail looks through headers in the following order:
2071 Resent-Sender: (ignored if it doesn't contain an @ or !)
2072 Sender: (ignored if it doesn't contain an @ or !)
2079 The originating address is used for logging, and to set the MAIL FROM
2080 address when forwarding to SMTP. This order is intended to cope
2081 gracefully with receiving mailing list messages in multidrop mode. The
2082 intent is that if a local address doesn't exist, the bounce message
2083 won't be returned blindly to the author or to the list itself, but
2084 rather to the list manager (which is less annoying).
2086 In multidrop mode, destination headers are processed as follows:
2087 First, fetchmail looks for the Received: header (or whichever one is
2088 specified by the 'envelope' option) to determine the local
2089 recipient address. If the mail is addressed to more than one recipient,
2090 the Received line won't contain any information regarding recipient addresses.
2092 Then fetchmail looks for the Resent-To:, Resent-Cc:, and Resent-Bcc:
2093 lines. If they exist, they should contain the final recipients and
2094 have precedence over their To:/Cc:/Bcc: counterparts. If the Resent\-*
2095 lines don't exist, the To:, Cc:, Bcc: and Apparently-To: lines are
2096 looked for. (The presence of a Resent\-To: is taken to imply that the
2097 person referred by the To: address has already received the original
2100 .SH CONFIGURATION EXAMPLES
2101 Note that although there are password declarations in a good many
2102 of the examples below, this is mainly for illustrative purposes.
2103 We recommend stashing account/password pairs in your $HOME/.netrc
2104 file, where they can be used not just by fetchmail but by ftp(1) and
2110 poll SERVERNAME protocol PROTOCOL username NAME password PASSWORD
2116 poll pop.provider.net protocol pop3 username "jsmith" password "secret1"
2119 Or, using some abbreviations:
2122 poll pop.provider.net proto pop3 user "jsmith" password "secret1"
2125 Multiple servers may be listed:
2128 poll pop.provider.net proto pop3 user "jsmith" pass "secret1"
2129 poll other.provider.net proto pop2 user "John.Smith" pass "My^Hat"
2132 Here's a version of those two with more whitespace and some noise words:
2135 poll pop.provider.net proto pop3
2136 user "jsmith", with password secret1, is "jsmith" here;
2137 poll other.provider.net proto pop2:
2138 user "John.Smith", with password "My^Hat", is "John.Smith" here;
2141 This version is much easier to read and doesn't cost significantly
2142 more (parsing is done only once, at startup time).
2145 If you need to include whitespace in a parameter string, enclose the
2146 string in double quotes. Thus:
2149 poll mail.provider.net with proto pop3:
2150 user "jsmith" there has password "u can't krak this"
2151 is jws here and wants mda "/bin/mail"
2154 You may have an initial server description headed by the keyword
2155 \&'defaults' instead of 'poll' followed by a name. Such a record
2156 is interpreted as defaults for all queries to use. It may be overwritten
2157 by individual server descriptions. So, you could write:
2162 poll pop.provider.net
2164 poll mail.provider.net
2165 user "jjsmith" there has password "secret2"
2168 It's possible to specify more than one user per server (this is only
2169 likely to be useful when running fetchmail in daemon mode as root).
2170 The 'user' keyword leads off a user description, and every user specification
2171 in a multi-user entry must include it. Here's an example:
2174 poll pop.provider.net proto pop3 port 3111
2175 user "jsmith" with pass "secret1" is "smith" here
2176 user jones with pass "secret2" is "jjones" here keep
2179 This associates the local username 'smith' with the pop.provider.net
2180 username 'jsmith' and the local username 'jjones' with the
2181 pop.provider.net username 'jones'. Mail for 'jones' is kept on the
2182 server after download.
2184 Here's what a simple retrieval configuration for a multi-drop mailbox
2188 poll pop.provider.net:
2189 user maildrop with pass secret1 to golux 'hurkle'='happy' snark here
2192 This says that the mailbox of account 'maildrop' on the server is a
2193 multi-drop box, and that messages in it should be parsed for the
2194 server user names 'golux', 'hurkle', and 'snark'. It further
2195 specifies that 'golux' and 'snark' have the same name on the
2196 client as on the server, but mail for server user 'hurkle' should be
2197 delivered to client user 'happy'.
2199 Here's an example of another kind of multidrop connection:
2202 poll pop.provider.net localdomains loonytoons.org toons.org:
2203 user maildrop with pass secret1 to * here
2206 This also says that the mailbox of account 'maildrop' on the server is
2207 a multi-drop box. It tells fetchmail that any address in the
2208 loonytoons.org or toons.org domains (including sub-domain addresses like
2209 \&'joe@daffy.loonytoons.org') should be passed through to the local SMTP
2210 listener without modification. Be careful of mail loops if you do this!
2212 Here's an example configuration using ssh and the plugin option. The
2213 queries are made directly on the stdin and stdout of imapd via ssh.
2214 Note that in this setup, IMAP authentication can be skipped.
2217 poll mailhost.net with proto imap:
2218 plugin "ssh %h /usr/sbin/imapd" auth ssh;
2219 user esr is esr here
2222 .SH THE USE AND ABUSE OF MULTIDROP MAILBOXES
2223 Use the multiple-local-recipients feature with caution -- it can bite.
2224 All multidrop features are ineffective in ETRN and ODMR modes.
2226 Also, note that in multidrop mode duplicate mails are suppressed. A
2227 piece of mail is considered duplicate if it has the same message-ID as
2228 the message immediately preceding and more than one addressee. Such
2229 runs of messages may be generated when copies of a message addressed
2230 to multiple users are delivered to a multidrop box.
2232 .SS Header vs. Envelope addresses
2233 The fundamental problem is that by having your mailserver toss several
2234 peoples' mail in a single maildrop box, you may have thrown away
2235 potentially vital information about who each piece of mail was
2236 actually addressed to (the 'envelope address', as opposed to the
2237 header addresses in the RFC822 To/Cc headers - the Bcc is not available
2238 at the receiving end). This 'envelope address' is the address you need
2239 in order to reroute mail properly.
2243 can deduce the envelope address. If the mailserver MTA is
2245 and the item of mail had just one recipient, the MTA will have written
2246 a 'by/for' clause that gives the envelope addressee into its Received
2247 header. But this doesn't work reliably for other MTAs, nor if there is
2248 more than one recipient. By default, \fIfetchmail\fR looks for
2249 envelope addresses in these lines; you can restore this default with
2250 \&\-E "Received" or 'envelope Received'.
2252 .B As a better alternative,
2253 some SMTP listeners and/or mail servers insert a header
2254 in each message containing a copy of the envelope addresses. This
2255 header (when it exists) is often 'X\-Original\-To', 'Delivered\-To' or
2256 \&'X\-Envelope\-To'. Fetchmail's assumption about this can be changed with
2257 the \-E or 'envelope' option. Note that writing an envelope header of
2258 this kind exposes the names of recipients (including blind-copy
2259 recipients) to all receivers of the messages, so the upstream must store
2260 one copy of the message per recipient to avoid becoming a privacy problem.
2262 Postfix, since version 2.0, writes an X\-Original\-To: header which
2263 contains a copy of the envelope as it was received.
2265 Qmail and Postfix generally write a 'Delivered\-To' header upon
2266 delivering the message to the mail spool and use it to avoid mail loops.
2267 Qmail virtual domains however will prefix the user name with a string
2268 that normally matches the user's domain. To remove this prefix you can
2269 use the \-Q or 'qvirtual' option.
2271 Sometimes, unfortunately, neither of these methods works. That is the
2272 point when you should contact your ISP and ask them to provide such an
2273 envelope header, and you should not use multidrop in this situation.
2274 When they all fail, fetchmail must fall back on the contents of To/Cc
2275 headers (Bcc headers are not available - see below) to try to determine
2276 recipient addressees -- and these are unreliable.
2277 In particular, mailing-list software often ships mail with only
2278 the list broadcast address in the To header.
2280 .B Note that a future version of fetchmail may remove To/Cc parsing!
2284 cannot deduce a recipient address that is local, and the intended
2285 recipient address was anyone other than fetchmail's invoking user,
2286 .B mail will get lost.
2287 This is what makes the multidrop feature risky without proper envelope
2290 A related problem is that when you blind-copy a mail message, the Bcc
2291 information is carried \fIonly\fR as envelope address (it's removed from
2292 the headers by the sending mail server, so fetchmail can see it only if
2293 there is an X-\Envelope\-To header). Thus, blind-copying to someone who
2294 gets mail over a fetchmail multidrop link will fail unless the the
2295 mailserver host routinely writes X\-Envelope\-To or an equivalent header
2296 into messages in your maildrop.
2298 \fBIn conclusion, mailing lists and Bcc'd mail can only work if the
2299 server you're fetching from (1) stores one copy of the message per
2300 recipient in \fBIyour\fP domain and (2) records the envelope
2301 information in a special header (X\-Original\-To, Delivered\-To,
2302 X\-Envelope\-To).\fR
2304 .SS Good Ways To Use Multidrop Mailboxes
2305 Multiple local names can be used to administer a mailing list from the
2306 client side of a \fIfetchmail\fR collection. Suppose your name is
2307 \&'esr', and you want to both pick up your own mail and maintain a mailing
2308 list called (say) "fetchmail-friends", and you want to keep the alias
2309 list on your client machine.
2311 On your server, you can alias 'fetchmail\-friends' to 'esr'; then, in
2312 your \fI.fetchmailrc\fR, declare 'to esr fetchmail\-friends here'.
2313 Then, when mail including 'fetchmail\-friends' as a local address
2314 gets fetched, the list name will be appended to the list of
2315 recipients your SMTP listener sees. Therefore it will undergo alias
2316 expansion locally. Be sure to include 'esr' in the local alias
2317 expansion of fetchmail\-friends, or you'll never see mail sent only to
2318 the list. Also be sure that your listener has the "me-too" option set
2319 (sendmail's \-oXm command-line option or OXm declaration) so your name
2320 isn't removed from alias expansions in messages you send.
2322 This trick is not without its problems, however. You'll begin to see
2323 this when a message comes in that is addressed only to a mailing list
2324 you do \fInot\fR have declared as a local name. Each such message
2325 will feature an 'X\-Fetchmail\-Warning' header which is generated
2326 because fetchmail cannot find a valid local name in the recipient
2327 addresses. Such messages default (as was described above) to being
2328 sent to the local user running
2330 but the program has no way to know that that's actually the right thing.
2332 .SS Bad Ways To Abuse Multidrop Mailboxes
2333 Multidrop mailboxes and
2335 serving multiple users in daemon mode do not mix. The problem, again, is
2336 mail from mailing lists, which typically does not have an individual
2337 recipient address on it. Unless
2339 can deduce an envelope address, such mail will only go to the account
2340 running fetchmail (probably root). Also, blind-copied users are very
2341 likely never to see their mail at all.
2343 If you're tempted to use
2345 to retrieve mail for multiple users from a single mail drop via POP or
2346 IMAP, think again (and reread the section on header and envelope
2347 addresses above). It would be smarter to just let the mail sit in the
2348 mailserver's queue and use fetchmail's ETRN or ODMR modes to trigger
2349 SMTP sends periodically (of course, this means you have to poll more
2350 frequently than the mailserver's expiry period). If you can't arrange
2351 this, try setting up a UUCP feed.
2353 If you absolutely \fImust\fR use multidrop for this purpose, make sure
2354 your mailserver writes an envelope-address header that fetchmail can
2355 see. Otherwise you \fIwill\fR lose mail and it \fIwill\fR come back
2358 .SS Speeding Up Multidrop Checking
2359 Normally, when multiple users are declared
2361 extracts recipient addresses as described above and checks each host
2362 part with DNS to see if it's an alias of the mailserver. If so, the
2363 name mappings described in the "to ... here" declaration are done and
2364 the mail locally delivered.
2366 This is a convenient but also slow method. To speed
2367 it up, pre-declare mailserver aliases with 'aka'; these are checked
2368 before DNS lookups are done. If you're certain your aka list contains
2370 DNS aliases of the mailserver (and all MX names pointing at it - note
2371 this may change in a future version)
2372 you can declare 'no dns' to suppress DNS lookups entirely and
2373 \fIonly\fR match against the aka list.
2376 To facilitate the use of
2378 in shell scripts, an exit code is returned to give an indication
2379 of what occurred during a given connection.
2381 The exit codes returned by
2385 One or more messages were successfully retrieved (or, if the \-c option
2386 was selected, were found waiting but not retrieved).
2388 There was no mail awaiting retrieval. (There may have been old mail still
2389 on the server but not selected for retrieval.)
2391 An error was encountered when attempting to open a socket to retrieve
2392 mail. If you don't know what a socket is, don't worry about it --
2393 just treat this as an 'unrecoverable error'. This error can also be
2394 because a protocol fetchmail wants to use is not listed in /etc/services.
2396 The user authentication step failed. This usually means that a bad
2397 user-id, password, or APOP id was specified. Or it may mean that you
2398 tried to run fetchmail under circumstances where it did not have
2399 standard input attached to a terminal and could not prompt for a
2402 Some sort of fatal protocol error was detected.
2404 There was a syntax error in the arguments to
2407 The run control file had bad permissions.
2409 There was an error condition reported by the server. Can also
2412 timed out while waiting for the server.
2414 Client-side exclusion error. This means
2416 either found another copy of itself already running, or failed in such
2417 a way that it isn't sure whether another copy is running.
2419 The user authentication step failed because the server responded "lock
2420 busy". Try again after a brief pause! This error is not implemented
2421 for all protocols, nor for all servers. If not implemented for your
2422 server, "3" will be returned instead, see above. May be returned when
2423 talking to qpopper or other servers that can respond with "lock busy"
2424 or some similar text containing the word "lock".
2428 run failed while trying to do an SMTP port open or transaction.
2430 Fatal DNS error. Fetchmail encountered an error while performing
2431 a DNS lookup at startup and could not proceed.
2433 BSMTP batch file could not be opened.
2435 Poll terminated by a fetch limit (see the \-\-fetchlimit option).
2437 Server busy indication.
2439 Server timed out during an IMAP IDLE.
2441 Internal error. You should see a message on standard error with
2446 queries more than one host, return status is 0 if \fIany\fR query
2447 successfully retrieved mail. Otherwise the returned error status is
2448 that of the last host queried.
2453 default run control file
2456 default location of file associating hosts with last message IDs seen
2457 (used only with newer RFC1939-compliant POP3 servers supporting the
2461 lock file to help prevent concurrent runs (non-root mode).
2464 your FTP run control file, which (if present) will be searched for
2465 passwords as a last resort before prompting for one interactively.
2467 /var/run/fetchmail.pid
2468 lock file to help prevent concurrent runs (root mode, Linux systems).
2471 lock file to help prevent concurrent runs (root mode, systems without /var/run).
2474 If the FETCHMAILUSER variable is set, it is used as the name of the
2475 calling user (default local name) for purposes such as mailing error
2476 notifications. Otherwise, if either the LOGNAME or USER variable is
2477 correctly set (e.g. the corresponding UID matches the session user ID)
2478 then that name is used as the default local name. Otherwise
2479 \fBgetpwuid\fR(3) must be able to retrieve a password entry for the
2480 session ID (this elaborate logic is designed to handle the case of
2481 multiple names per userid gracefully).
2483 If the environment variable FETCHMAILHOME is set to a valid and
2484 existing directory name, fetchmail will read $FETCHMAILHOME/fetchmailrc
2485 (the dot is missing in this case), $FETCHMAILHOME/.fetchids and
2486 $FETCHMAILHOME/.fetchmail.pid rather than from the user's home
2487 directory. The .netrc file is always looked for in the the invoking
2488 user's home directory regardless of FETCHMAILHOME's setting.
2490 If the HOME_ETC variable is set, fetchmail will read
2491 $HOME_ETC/.fetchmailrc instead of ~/.fetchmailrc.
2493 If HOME_ETC and FETCHMAILHOME are set, HOME_ETC will be ignored.
2498 daemon is running as root, SIGHUP wakes it up from its sleep phase and
2499 forces a poll of all non-skipped servers (this is in accordance with
2500 the usual conventions for system daemons).
2504 is running in daemon mode as non-root, use SIGUSR1 to wake it (this is
2505 so SIGHUP due to logout can retain the default action of killing it).
2509 in foreground while a background fetchmail is running will do
2510 whichever of these is appropriate to wake it up.
2512 .SH BUGS AND KNOWN PROBLEMS
2514 Please check the \fBNEWS\fP file that shipped with fetchmail for more
2515 known bugs than those listed here.
2517 The assumptions that the DNS and in particular the checkalias options
2518 make are not often sustainable. For instance, it has become uncommon for
2519 an MX server to be a POP3 or IMAP server at the same time. Therefore the
2520 MX lookups may go away in a future release.
2522 The mda and plugin options interact badly. In order to collect error
2523 status from the MDA, fetchmail has to change its normal signal
2524 handling so that dead plugin processes don't get reaped until the end
2525 of the poll cycle. This can cause resource starvation if too many
2526 zombies accumulate. So either don't deliver to a MDA using plugins or
2527 risk being overrun by an army of undead.
2529 The \-\-interface option does not support IPv6 and it is doubtful if it
2530 ever will, since there is no portable way to query interface IPv6
2533 The RFC822 address parser used in multidrop mode chokes on some
2534 @-addresses that are technically legal but bizarre. Strange uses of
2535 quoting and embedded comments are likely to confuse it.
2537 In a message with multiple envelope headers, only the last one
2538 processed will be visible to fetchmail.
2540 Use of some of these protocols requires that the program send
2541 unencrypted passwords over the TCP/IP connection to the mailserver.
2542 This creates a risk that name/password pairs might be snaffled with a
2543 packet sniffer or more sophisticated monitoring software. Under Linux
2544 and FreeBSD, the \-\-interface option can be used to restrict polling to
2545 availability of a specific interface device with a specific local or
2546 remote IP address, but snooping is still possible if (a) either host
2547 has a network device that can be opened in promiscuous mode, or (b)
2548 the intervening network link can be tapped. We recommend the use of
2550 tunnelling to not only shroud your passwords but encrypt the entire
2553 Use of the %F or %T escapes in an mda option could open a security
2554 hole, because they pass text manipulable by an attacker to a shell
2555 command. Potential shell characters are replaced by '_' before
2556 execution. The hole is further reduced by the fact that fetchmail
2557 temporarily discards any suid privileges it may have while running the
2558 MDA. For maximum safety, however, don't use an mda command containing
2559 %F or %T when fetchmail is run from the root account itself.
2561 Fetchmail's method of sending bounces due to errors or spam-blocking and
2562 spam bounces requires that port 25 of localhost be available for sending
2567 while a background instance is running and break the syntax, the
2568 background instance will die silently. Unfortunately, it can't
2569 die noisily because we don't yet know whether syslog should be enabled.
2570 On some systems, fetchmail dies quietly even if there is no syntax
2571 error; this seems to have something to do with buggy terminal ioctl
2574 The \-f\~\- option (reading a configuration from stdin) is incompatible
2575 with the plugin option.
2577 The 'principal' option only handles Kerberos IV, not V.
2579 Interactively entered passwords are truncated after 63 characters. If
2580 you really need to use a longer password, you will have to use a
2583 A backslash as the last character of a configuration file will be
2584 flagged as a syntax error rather than ignored.
2586 Send comments, bug reports, gripes, and the like to the
2587 fetchmail\-devel list <fetchmail\-devel@lists.berlios.de>. An HTML FAQ is
2588 available at the fetchmail home page; surf to
2589 http://fetchmail.berlios.de/ or do a WWW search for pages with
2590 \&'fetchmail' in their titles.
2593 Fetchmail is currently maintained by Matthias Andree and Rob Funk with
2594 major assistance from Sunil Shetye (for code) and Rob MacGregor (for the
2597 Most of the code is from Eric S. Raymond <esr@snark.thyrsus.com>. Too
2598 many other people to name here have contributed code and patches.
2600 This program is descended from and replaces
2602 by Carl Harris <ceharris@mal.com>; the internals have become quite different,
2603 but some of its interface design is directly traceable to that
2606 This manual page has been improved by R.\ Hannes Beinert and H\['e]ctor
2610 mutt(1), elm(1), mail(1), sendmail(8), popd(8), imapd(8), netrc(5)
2612 The fetchmail home page: <http://fetchmail.berlios.de/>
2614 The maildrop home page: <http://www.courier-mta.org/maildrop/>
2615 .SH APPLICABLE STANDARDS
2617 Note that this list is just a collection of references and not a
2618 statement as to the actual protocol conformance or requirements in
2622 RFC 821, RFC 2821, RFC 1869, RFC 1652, RFC 1870, RFC 1983, RFC 1985,
2626 RFC 822, RFC 2822, RFC 1123, RFC 1892, RFC 1894.
2632 RFC 1081, RFC 1225, RFC 1460, RFC 1725, RFC 1734, RFC 1939, RFC 1957,
2636 RFC 1460, RFC 1725, RFC 1939.
2645 RFC 1730, RFC 1731, RFC 1732, RFC 2060, RFC 2061, RFC 2195, RFC 2177,
projects / ~andy / fetchmail / blob