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.
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
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
187 Keep retrieved messages on the remote mailserver. Normally, messages
188 are deleted from the folder on the mailserver after they have been retrieved.
191 option causes retrieved messages to remain in your folder on the
192 mailserver. This option does not work with ETRN or ODMR.
196 Delete retrieved messages from the remote mailserver. This
197 option forces retrieved mail to be deleted. It may be useful if
198 you have specified a default of \fBkeep\fR in your
199 \&\fI.fetchmailrc\fR. This option is forced on with ETRN and ODMR.
202 POP3/IMAP only. This is a dangerous option and can cause mail loss when
203 used improperly. It deletes old (seen) messages from the mailserver
204 before retrieving new messages. Warning: This can cause mail loss if
205 you check your mail with other clients than fetchmail, and cause
206 fetchmail to delete a message it had never fetched before. Similarly, if
207 your local MTA hangs and fetchmail is aborted, the next time you run
208 fetchmail, it will delete mail that was never delivered to you. You
209 should probably not use this option in your configuration file. What you
210 probably want is the default setting: if you don't specify '-k', then
211 fetchmail will automatically delete messages after successful
212 delivery. This option does not work with ETRN and ODMR.
215 POP3/IMAP only, since version 6.3.0. Delete oversized messages from the
216 mailserver before retrieving new messages. The size limit should be
217 separately sepecified with the --limit option. This option does not
218 work with ETRN or ODMR.
219 .SS Protocol and Query Options
221 .B \-p <proto> | \-\-proto <proto> | \-\-protocol <proto>
222 (Keyword: proto[col])
223 Specify the protocol to use when communicating with the remote
224 mailserver. If no protocol is specified, the default is AUTO.
226 may be one of the following:
229 Tries IMAP, POP3, and POP2 (skipping any of these for which support
230 has not been compiled in).
232 Post Office Protocol 2 (legacy, to be removed from future release)
234 Post Office Protocol 3
236 Use POP3 with old-fashioned MD5-challenge authentication.
238 Use POP3 with RPOP authentication.
240 Use POP3 with Kerberos V4 authentication on port 1109.
242 Use POP3 with Demon Internet's SDPS extensions.
244 IMAP2bis, IMAP4, or IMAP4rev1 (\fIfetchmail\fR autodetects their capabilities).
246 Use the ESMTP ETRN option.
248 Use the the On-Demand Mail Relay ESMTP profile.
251 All these alternatives work in basically the same way (communicating
252 with standard server daemons to fetch mail already delivered to a
253 mailbox on the server) except ETRN and ODMR. The ETRN mode
254 allows you to ask a compliant ESMTP server (such as BSD sendmail at
255 release 8.8.0 or higher) to immediately open a sender-SMTP connection
256 to your client machine and begin forwarding any items addressed to
257 your client machine in the server's queue of undelivered mail. The
258 ODMR mode requires an ODMR-capable server and works similarly to
259 ETRN, except that it does not require the client machine to have
264 Force UIDL use (effective only with POP3). Force client-side tracking
265 of 'newness' of messages (UIDL stands for "unique ID listing" and is
266 described in RFC1939). Use with 'keep' to use a mailbox as a baby
267 news drop for a group of users. The fact that seen messages are skipped
268 is logged, unless error logging is done through syslog while running in
269 daemon mode. Note that fetchmail may automatically enable this option
270 depending on upstream server capabilities. Note also that this option
271 may be removed and forced enabled in a future fetchmail version.
274 .B \-\-service <servicename>
275 (Keyword: service) Since version 6.3.0.
276 The service option permits you to specify a service name to connect to.
277 You can specify a decimal port number here, if your services database
278 lacks the required service-port assignments. See the FAQ item R12 and
279 the \-\-ssl documentation for details. This replaces the older \-\-port
282 .B \-P <portnumber> | \-\-port <portnumber>
284 Obsolete version of \-\-service that does not take service names.
286 this option may be removed from a future version.
288 .B \-\-principal <principal>
290 The principal option permits you to specify a service principal for
291 mutual authentication. This is applicable to POP3 or IMAP with Kerberos
294 .B \-t <seconds> | \-\-timeout <seconds>
296 The timeout option allows you to set a server-nonresponse
297 timeout in seconds. If a mailserver does not send a greeting message
298 or respond to commands for the given number of seconds,
299 \fIfetchmail\fR will hang up on it. Without such a timeout
300 \fIfetchmail\fR might hang up indefinitely trying to fetch mail from a
301 down host. This would be particularly annoying for a \fIfetchmail\fR
302 running in background. There is a default timeout which fetchmail\~-V
303 will report. If a given connection receives too many timeouts in
304 succession, fetchmail will consider it wedged and stop retrying,
305 the calling user will be notified by email if this happens.
307 .B \-\-plugin <command>
308 (Keyword: plugin) The plugin option allows you to use an external
309 program to establish the TCP connection. This is useful if you want
310 to use socks, SSL, ssh, or need some special firewalling setup. The
311 program will be looked up in $PATH and can optionally be passed the
312 hostname and port as arguments using "%h" and "%p" respectively (note
313 that the interpolation logic is rather primitive, and these token must
314 be bounded by whitespace or beginning of string or end of string).
315 Fetchmail will write to the plugin's stdin and read from the plugin's
318 .B \-\-plugout <command>
320 Identical to the plugin option above, but this one is used for the SMTP
321 connections (which will probably not need it, so it has been separated
324 .B \-r <name> | \-\-folder <name>
326 Causes a specified non-default mail folder on the mailserver (or
327 comma-separated list of folders) to be retrieved. The syntax of the
328 folder name is server-dependent. This option is not available under
332 (Keyword: tracepolls)
333 Tell fetchmail to poll trace information in the form 'polling %s
334 account %s' to the Received line it generates, where the %s parts are
335 replaced by the user's remote name and the poll label (the Received
336 header also normally includes the server's true name). This can be
337 used to facilitate mail filtering based on the account it is being
342 Causes the connection to the mail server to be encrypted via SSL. Connect
343 to the server using the specified base protocol over a connection secured
344 by SSL. SSL support must be present at the server.
346 If no port is specified, the connection is attempted to the well known
347 port of the SSL version of the base protocol. This is generally a
348 different port than the port used by the base protocol. For IMAP, this
349 is port 143 for the clear protocol and port 993 for the SSL secured
350 protocol, for POP3, it is port 110 for the cleartext and port 995 for
351 the encrypted variant.
353 If your system lacks the corresponding entries from /etc/services, see
354 the \-\-service option and specify the numeric port number as given in
355 the previous paragraph (unless your ISP had directed you to different
356 ports, which is uncommon however).
358 .B \-\-sslcert <name>
360 Specifies the file name of the client side public SSL certificate. Some
361 SSL encrypted servers may require client side keys and certificates for
362 authentication. In most cases, this is optional. This specifies
363 the location of the public key certificate to be presented to the server
364 at the time the SSL session is established. It is not required (but may
365 be provided) if the server does not require it. Some servers may
366 require it, some servers may request it but not require it, and some
367 servers may not request it at all. It may be the same file
368 as the private key (combined key and certificate file) but this is not
373 Specifies the file name of the client side private SSL key. Some SSL
374 encrypted servers may require client side keys and certificates for
375 authentication. In most cases, this is optional. This specifies
376 the location of the private key used to sign transactions with the server
377 at the time the SSL session is established. It is not required (but may
378 be provided) if the server does not require it. Some servers may
379 require it, some servers may request it but not require it, and some
380 servers may not request it at all. It may be the same file
381 as the public key (combined key and certificate file) but this is not
382 recommended. If a password is required to unlock the key, it will be
383 prompted for at the time just prior to establishing the session to the
384 server. This can cause some complications in daemon mode.
386 .B \-\-sslproto <name>
388 Forces an SSL protocol. Possible values are '\fBssl2\fR',
389 \&'\fBssl3\fR', '\fBssl23\fR', and '\fBtls1\fR'. Try this if the default
390 handshake does not work for your server. To defeat automatic TLSv1
391 negotiation when the server advertises STARTTLS or STLS, use \fB''\fR or
392 \&'\fBssl23\fR'. The default is to try appropriate protocols depending
397 Causes fetchmail to strictly check the server certificate against a set of
398 local trusted certificates (see the \fBsslcertpath\fR option). If the server
399 certificate is not signed by one of the trusted ones (directly or indirectly),
400 the SSL connection will fail. This checking should prevent man-in-the-middle
401 attacks against the SSL connection. Note that CRLs are seemingly not currently
402 supported by OpenSSL in certificate verification! Your system clock should
403 be reasonably accurate when using this option!
405 .B \-\-sslcertpath <directory>
406 (Keyword: sslcertpath)
407 Sets the directory fetchmail uses to look up local certificates. The default
408 is your OpenSSL default one. The directory must be hashed as OpenSSL expects
409 it - every time you add or modify a certificate in the directory, you need
410 to use the \fBc_rehash\fR tool (which comes with OpenSSL in the tools/
413 .B \-\-sslfingerprint <fingerprint>
414 (Keyword: sslfingerprint)
415 Specify the fingerprint of the server key (an MD5 hash of the key) in
416 hexadecimal notation with colons separating groups of two digits. The letter
417 hex digits must be in upper case. This is the default format OpenSSL uses,
418 and the one fetchmail uses to report the fingerprint when an SSL connection
419 is established. When this is specified, fetchmail will compare the server key
420 fingerprint with the given one, and the connection will fail if they do not
421 match. This can be used to prevent man-in-the-middle attacks.
423 To obtain the fingerprint of a certificate stored in the file cert.pem,
427 openssl x509 -in cert.pem -noout -fingerprint
432 .SS Delivery Control Options
434 .B \-S <hosts> | \-\-smtphost <hosts>
435 (Keyword: smtp[host])
436 Specify a hunt list of hosts to forward mail to (one or more
437 hostnames, comma-separated). Hosts are tried in list order; the first
438 one that is up becomes the forwarding target for the current run.
439 The default depends on the authentication methods and protocols used on
440 the active servers. If this option is not specified, 'localhost' is used
441 as a default. Each hostname may have a port number following the host
442 name. The port number is separated from the host name by a slash; the
443 default port is 25 (or "smtp" under IPv6). If you specify an absolute
444 path name (beginning with a /), it will be interpreted as the name of a
445 UNIX socket accepting LMTP connections (such as is supported by the
450 --smtphost server1,server2/2525,server3,/var/imap/socket/lmtp
453 This option can be used with ODMR, and will make fetchmail a relay
454 between the ODMR server and SMTP or LMTP receiver.
456 .B \-\-fetchdomains <hosts>
457 (Keyword: fetchdomains)
458 In ETRN or ODMR mode, this option specifies the list of domains the
459 server should ship mail for once the connection is turned around. The
460 default is the FQDN of the machine running
463 .B \-D <domain> | \-\-smtpaddress <domain>
464 (Keyword: smtpaddress) Specify the domain to be appended to addresses
465 in RCPT TO lines shipped to SMTP. The name of the SMTP server (as
466 specified by --smtphost, which see) is used when this is not specified.
468 .B \-\-smtpname <user@domain>
470 Specify the domain and user to be put in RCPT TO lines shipped to SMTP.
471 The default user is the current local user.
473 .B \-Z <nnn> | \-\-antispam <nnn[, nnn]...>
475 Specifies the list of numeric SMTP errors that are to be interpreted
476 as a spam-block response from the listener. A value of -1 disables
477 this option. For the command-line option, the list values should
480 .B \-m <command> | \-\-mda <command>
481 (Keyword: mda) You can force mail to be passed to an MDA directly
482 (rather than forwarded to port 25) with the --mda or -m option. To
483 avoid losing mail, use this option only with MDAs like maildrop, procmail or
484 sendmail that return a nonzero status on disk-full and other
485 resource-exhaustion errors; the nonzero status tells fetchmail that
486 delivery failed and prevents the message from being deleted off the
487 server. If \fIfetchmail\fR is running as root, it sets its user id to
488 that of the target user while delivering mail through an MDA. Some
489 possible MDAs are "/usr/sbin/sendmail -i -f %F %T", "/usr/bin/deliver"
490 and "/usr/bin/procmail -d %T" (but the latter is usually redundant as
491 it's what SMTP listeners normally forward to). Local delivery
492 addresses will be inserted into the MDA command wherever you place a
493 %T; the mail message's From address will be inserted where you place
494 an %F. \fBDO NOT ENCLOSE THE %F OR %T STRING IN SINGLE QUOTES!\fR For
495 both %T and %F, fetchmail encloses the addresses in single quotes ('),
496 after removing any single quotes they may contain, before the MDA
497 command is passed to the shell. Do \fINOT\fR use an MDA invocation
498 like "sendmail -i -t" that dispatches on the contents of To/Cc/Bcc, it
499 will create mail loops and bring the just wrath of many postmasters
500 down upon your head. Also, do \fInot\fR try to combine multidrop
501 mode with an MDA such as procmail that can only accept one address;
506 Cause delivery via LMTP (Local Mail Transfer Protocol). A service
507 host and port \fBmust\fR be explicitly specified on each host in the
508 smtphost hunt list (see above) if this option is selected; the default
509 port 25 will (in accordance with RFC 2033) not be accepted.
511 .B \-\-bsmtp <filename>
513 Append fetched mail to a BSMTP file. This simply contains the SMTP
514 commands that would normally be generated by fetchmail when passing
515 mail to an SMTP listener daemon. An argument of '-' causes the mail
516 to be written to standard output. Note that fetchmail's
517 reconstruction of MAIL FROM and RCPT TO lines is not guaranteed
518 correct; the caveats discussed under THE USE AND ABUSE OF MULTIDROP
519 MAILBOXES below apply.
520 .SS Resource Limit Control Options
522 .B \-l <maxbytes> | \-\-limit <maxbytes>
523 (Keyword: limit) Takes a maximum octet size argument. Messages larger
524 than this size will not be fetched and will be left on the server (in
525 foreground sessions, the progress messages will note that they are
526 "oversized"). If the fetch protocol permits (in particular, under
527 IMAP or POP3 without the fetchall option) the message will not be
530 An explicit --limit of 0 overrides any limits set in your
531 run control file. This option is intended for those needing to
532 strictly control fetch time due to expensive and variable phone rates.
534 Combined with --limitflush, it can be used to delete oversized
535 messages waiting on a server. In daemon mode, oversize notifications
536 are mailed to the calling user (see the --warnings option). This
537 option does not work with ETRN or ODMR.
539 .B \-w <interval> | \-\-warnings <interval>
541 Takes an interval in seconds. When you call
543 with a 'limit' option in daemon mode, this controls the interval at
544 which warnings about oversized messages are mailed to the calling user
545 (or the user specified by the 'postmaster' option). One such
546 notification is always mailed at the end of the the first poll that
547 the oversized message is detected. Thereafter, renotification is
548 suppressed until after the warning interval elapses (it will take
549 place at the end of the first following poll).
551 .B \-b <count> | \-\-batchlimit <count>
552 (Keyword: batchlimit)
553 Specify the maximum number of messages that will be shipped to an SMTP
554 listener before the connection is deliberately torn down and rebuilt
555 (defaults to 0, meaning no limit). An explicit --batchlimit of 0
556 overrides any limits set in your run control file. While
557 \fBsendmail\fR(8) normally initiates delivery of a message immediately
558 after receiving the message terminator, some SMTP listeners are not so
559 prompt. MTAs like \fIsmail\fR(8) may wait till the
560 delivery socket is shut down to deliver. This may produce annoying
561 delays when \fIfetchmail\fR is processing very large batches. Setting
562 the batch limit to some nonzero size will prevent these delays. This
563 option does not work with ETRN or ODMR.
565 .B \-B <number> | \-\-fetchlimit <number>
566 (Keyword: fetchlimit)
567 Limit the number of messages accepted from a given server in a single
568 poll. By default there is no limit. An explicit --fetchlimit of 0
569 overrides any limits set in your run control file.
570 This option does not work with ETRN or ODMR.
572 .B \-\-fetchsizelimit <number>
573 (Keyword: fetchsizelimit)
574 Limit the number of sizes of messages accepted from a given server in
575 a single transaction. This option is useful in reducing the delay in
576 downloading the first mail when there are too many mails in the
577 mailbox. By default, the limit is 100. If set to 0, sizes of all
578 messages are downloaded at the start.
579 This option does not work with ETRN or ODMR. For POP3, the only valid
582 .B \-\-fastuidl <number>
584 Do a binary instead of linear search for the first unseen UID. Binary
585 search avoids downloading the UIDs of all mails. This saves time
586 (especially in daemon mode) where downloading the same set of UIDs in
587 each poll is a waste of bandwidth. The number 'n' indicates how rarely
588 a linear search should be done. In daemon mode, linear search is used
589 once followed by binary searches in 'n-1' polls if 'n' is greater than
590 1; binary search is always used if 'n' is 1; linear search is always
591 used if 'n' is 0. In non-daemon mode, binary search is used if 'n' is
592 1; otherwise linear search is used.
593 This option works with POP3 only.
595 .B \-e <count> | \-\-expunge <count>
597 Arrange for deletions to be made final after a given number of
598 messages. Under POP2 or POP3, fetchmail cannot make deletions final
599 without sending QUIT and ending the session -- with this option on,
600 fetchmail will break a long mail retrieval session into multiple
601 sub-sessions, sending QUIT after each sub-session. This is a good
602 defense against line drops on POP3 servers that do not do the
603 equivalent of a QUIT on hangup. Under IMAP,
605 normally issues an EXPUNGE command after each deletion in order to
606 force the deletion to be done immediately. This is safest when your
607 connection to the server is flaky and expensive, as it avoids
608 resending duplicate mail after a line hit. However, on large
609 mailboxes the overhead of re-indexing after every message can slam the
610 server pretty hard, so if your connection is reliable it is good to do
611 expunges less frequently. Also note that some servers enforce a delay
612 of a few seconds after each quit, so fetchmail may not be able to get
613 back in immediately after an expunge -- you may see "lock busy" errors
614 if this happens. If you specify this option to an integer N,
617 to only issue expunges on every Nth delete. An argument of zero
618 suppresses expunges entirely (so no expunges at all will be done until
619 the end of run). This option does not work with ETRN or ODMR.
620 .SS Authentication Options
622 .B \-u <name> | \-\-user <name> | \-\-username <name>
623 (Keyword: user[name])
624 Specifies the user identification to be used when logging in to the mailserver.
625 The appropriate user identification is both server and user-dependent.
626 The default is your login name on the client machine that is running
628 See USER AUTHENTICATION below for a complete description.
630 .B \-I <specification> | \-\-interface <specification>
632 Require that a specific interface device be up and have a specific local
633 or remote IPv4 (IPv6 is not supported by this option yet) address (or
634 range) before polling. Frequently \fIfetchmail\fP
635 is used over a transient point-to-point TCP/IP link established directly
636 to a mailserver via SLIP or PPP. That is a relatively secure channel.
637 But when other TCP/IP routes to the mailserver exist (e.g. when the link
638 is connected to an alternate ISP), your username and password may be
639 vulnerable to snooping (especially when daemon mode automatically polls
640 for mail, shipping a clear password over the net at predictable
641 intervals). The --interface option may be used to prevent this. When
642 the specified link is not up or is not connected to a matching IP
643 address, polling will be skipped. The format is:
646 interface/iii.iii.iii.iii[/mmm.mmm.mmm.mmm]
649 The field before the first slash is the interface name (i.e. sl0, ppp0
650 etc.). The field before the second slash is the acceptable IP address.
651 The field after the second slash is a mask which specifies a range of
652 IP addresses to accept. If no mask is present 255.255.255.255 is
653 assumed (i.e. an exact match). This option is currently only supported
654 under Linux and FreeBSD. Please see the
656 section for below for FreeBSD specific information.
658 Note that this option may be removed from a future fetchmail version.
660 .B \-M <interface> | \-\-monitor <interface>
662 Daemon mode can cause transient links which are automatically taken down
663 after a period of inactivity (e.g. PPP links) to remain up
664 indefinitely. This option identifies a system TCP/IP interface to be
665 monitored for activity. After each poll interval, if the link is up but
666 no other activity has occurred on the link, then the poll will be
667 skipped. However, when fetchmail is woken up by a signal, the
668 monitor check is skipped and the poll goes through unconditionally.
669 This option is currently only supported under Linux and FreeBSD.
674 options to work for non root users under FreeBSD, the fetchmail binary
675 must be installed SGID kmem. This would be a security hole, but
676 fetchmail runs with the effective GID set to that of the kmem group
678 when interface data is being collected.
680 Note that this option may be removed from a future fetchmail version.
683 (Keyword: auth[enticate])
684 This option permits you to specify an authentication type (see USER
685 AUTHENTICATION below for details). The possible values are \fBany\fR,
686 \&\fBpassword\fR, \fBkerberos_v5\fR, \fBkerberos\fR (or, for
687 excruciating exactness, \fBkerberos_v4\fR), \fBgssapi\fR,
688 \fBcram-md5\fR, \fBotp\fR, \fBntlm\fR, \fBmsn\fR (only for POP3) and
689 \fBssh\fR. When \fBany\fR (the default) is specified, fetchmail tries
690 first methods that don't require a password (GSSAPI, KERBEROS\ IV,
691 KERBEROS\ 5); then it looks for methods that mask your password
692 (CRAM-MD5, X-OTP - note that NTLM and MSN are not autoprobed for POP3
693 and MSN is only supported for POP3); and only if the server doesn't
694 support any of those will it ship your password en clair. Other values
695 may be used to force various authentication methods
696 (\fBssh\fR suppresses authentication and is thus good for IMAP PREAUTH).
697 Any value other than \fBpassword\fR, \fBcram-md5\fR, \fBntlm\fR,
698 \&\fBmsn\fR or \fBotp\fR suppresses fetchmail's normal inquiry for a
699 password. Specify \fBssh\fR when you are using an end-to-end secure
700 connection such as an ssh tunnel; specify \fBgssapi\fR or
701 \&\fBkerberos_v4\fR if you are using a protocol variant that employs
702 GSSAPI or K4. Choosing KPOP protocol automatically selects Kerberos
703 authentication. This option does not work with ETRN.
704 .SS Miscellaneous Options
706 .B \-f <pathname> | \-\-fetchmailrc <pathname>
707 Specify a non-default name for the
709 run control file. The pathname argument must be either "-" (a single
710 dash, meaning to read the configuration from standard input) or a
711 filename. Unless the --version option is also on, a named file
712 argument must have permissions no more open than 0600 (u=rw,g=,o=) or
715 .B \-i <pathname> | \-\-idfile <pathname>
717 Specify an alternate name for the .fetchids file used to save POP3
720 .B \-n | \-\-norewrite
721 (Keyword: no rewrite)
724 edits RFC-822 address headers (To, From, Cc, Bcc, and Reply-To) in
725 fetched mail so that any mail IDs local to the server are expanded to
726 full addresses (@ and the mailserver hostname are appended). This enables
727 replies on the client to get addressed correctly (otherwise your
728 mailer might think they should be addressed to local users on the
729 client machine!). This option disables the rewrite. (This option is
730 provided to pacify people who are paranoid about having an MTA edit
731 mail headers and want to know they can prevent it, but it is generally
732 not a good idea to actually turn off rewrite.)
733 When using ETRN or ODMR, the rewrite option is ineffective.
735 .B \-E <line> | \-\-envelope <line>
736 (Keyword: envelope; Multidrop only)
738 In the configuration file, an enhanced syntax is used:
740 .B envelope [<count>] <line>
742 This option changes the header
744 assumes will carry a copy of the mail's envelope address. Normally
745 this is 'X-Envelope-To' but as this header is not standard, practice
746 varies. See the discussion of multidrop address handling below. As a
747 special case, 'envelope "Received"' enables parsing of sendmail-style
748 Received lines. This is the default, and it should not be necessary
749 unless you have globally disabled Received parsing with 'no envelope'
750 in the \fI.fetchmailrc\fR file.
752 The optional count argument (only available in the configuration file)
753 determines how many header lines of this kind are skipped. A count of 1
754 means: skip the first, take the second. A count of 2 means: skip the
755 first and second, take the third, and so on.
757 .B \-Q <prefix> | \-\-qvirtual <prefix>
758 (Keyword: qvirtual; Multidrop only)
759 The string prefix assigned to this option will be removed from the user
760 name found in the header specified with the \fIenvelope\fR option
761 (\fIbefore\fR doing multidrop name mapping or localdomain checking,
762 if either is applicable). This option is useful if you are using
764 to collect the mail for an entire domain and your ISP (or your mail
765 redirection provider) is using qmail.
766 One of the basic features of qmail is the
770 message header. Whenever qmail delivers a message to a local mailbox
771 it puts the username and hostname of the envelope recipient on this
772 line. The major reason for this is to prevent mail loops. To set up
773 qmail to batch mail for a disconnected site the ISP-mailhost will have
774 normally put that site in its 'Virtualhosts' control file so it will
775 add a prefix to all mail addresses for this site. This results in mail
776 .\" The \&@\& tries to stop HTML converters from making a mailto URL here.
777 sent to 'username\&@\&userhost.userdom.dom.com' having a
778 \&'Delivered-To:' line of the form:
780 Delivered-To: mbox-userstr-username\&@\&userhost.userdom.dom.com
782 The ISP can make the 'mbox-userstr-' prefix anything they choose
783 but a string matching the user host name is likely.
784 By using the option 'envelope Delivered-To:' you can make fetchmail reliably
785 identify the original envelope recipient, but you have to strip the
786 \&'mbox-userstr-' prefix to deliver to the correct user.
787 This is what this option is for.
792 file, interpret any command-line options specified, and dump a
793 configuration report to standard output. The configuration report is
794 a data structure assignment in the language Python. This option
795 is meant to be used with an interactive
803 Removed before version 6.3.0, the required underlying inet6_apps library
804 had been discontinued and is no longer available.
806 .SH USER AUTHENTICATION AND ENCRYPTION
807 All modes except ETRN require authentication of the client to the server.
808 Normal user authentication in
810 is very much like the authentication mechanism of
812 The correct user-id and password depend upon the underlying security
813 system at the mailserver.
815 If the mailserver is a Unix machine on which you have an ordinary user
816 account, your regular login name and password are used with
818 If you use the same login name on both the server and the client machines,
819 you needn't worry about specifying a user-id with the
821 option \-\- the default behavior is to use your login name on the
822 client machine as the user-id on the server machine. If you use a
823 different login name on the server machine, specify that login name
826 option. e.g. if your login name is 'jsmith' on a machine named 'mailgrunt',
831 fetchmail -u jsmith mailgrunt
833 The default behavior of
835 is to prompt you for your mailserver password before the connection is
836 established. This is the safest way to use
838 and ensures that your password will not be compromised. You may also specify
839 your password in your
841 file. This is convenient when using
843 in daemon mode or with scripts.
844 .SS Using netrc files
846 If you do not specify a password, and
848 cannot extract one from your
850 file, it will look for a
852 file in your home directory before requesting one interactively; if an
853 entry matching the mailserver is found in that file, the password will
854 be used. Fetchmail first looks for a match on poll name; if it finds none,
855 it checks for a match on via name. See the
857 man page for details of the syntax of the
859 file. To show a practical example, a .netrc might look like
863 machine hermes.example.org
868 You can repeat this block with different user information if you need to
869 provide more than one password.
871 This feature may allow you to avoid duplicating password
872 information in more than one file.
874 On mailservers that do not provide ordinary user accounts, your user-id and
875 password are usually assigned by the server administrator when you apply for
876 a mailbox on the server. Contact your server administrator if you don't know
877 the correct user-id and password for your mailbox account.
880 Early versions of POP3 (RFC1081, RFC1225) supported a crude form of
881 independent authentication using the
883 file on the mailserver side. Under this RPOP variant, a fixed
884 per-user ID equivalent to a password was sent in clear over a link to
885 a reserved port, with the command RPOP rather than PASS to alert the
886 server that it should do special checking. RPOP is supported
889 (you can specify 'protocol RPOP' to have the program send 'RPOP'
890 rather than 'PASS') but its use is strongly discouraged. This
891 facility was vulnerable to spoofing and was withdrawn in RFC1460.
893 RFC1460 introduced APOP authentication. In this variant of POP3,
894 you register an APOP password on your server host (the program
895 to do this with on the server is probably called \fIpopauth\fR(8)). You
896 put the same password in your
900 logs in, it sends a cryptographically secure hash of your password and
901 the server greeting time to the server, which can verify it by
902 checking its authorization database.
903 .SS Alternate authentication forms
905 If your \fIfetchmail\fR was built with Kerberos support and you specify
906 Kerberos authentication (either with --auth or the \fI.fetchmailrc\fR
907 option \fBauthenticate kerberos_v4\fR) it will try to get a Kerberos
908 ticket from the mailserver at the start of each query. Note: if
909 either the pollname or via name is 'hesiod', fetchmail will try to use
910 Hesiod to look up the mailserver.
912 If you use POP3 or IMAP with GSSAPI authentication, \fIfetchmail\fR will
913 expect the server to have RFC1731- or RFC1734-conformant GSSAPI
914 capability, and will use it. Currently this has only been tested over
915 Kerberos V, so you're expected to already have a ticket-granting
916 ticket. You may pass a username different from your principal name
917 using the standard \fB--user\fR command or by the \fI.fetchmailrc\fR
920 If your IMAP daemon returns the PREAUTH response in its greeting line,
921 fetchmail will notice this and skip the normal authentication step.
922 This can be useful, e.g. if you start imapd explicitly using ssh.
923 In this case you can declare the authentication value 'ssh' on that
924 site entry to stop \fI.fetchmail\fR from asking you for a password
927 If you are using POP3, and the server issues a one-time-password
928 challenge conforming to RFC1938, \fIfetchmail\fR will use your
929 password as a pass phrase to generate the required response. This
930 avoids sending secrets over the net unencrypted.
932 Compuserve's RPA authentication (similar to APOP) is supported. If you
933 compile in the support, \fIfetchmail\fR will try to perform an RPA pass-phrase
934 authentication instead of sending over the password en clair if it
935 detects "@compuserve.com" in the hostname.
937 If you are using IMAP, Microsoft's NTLM authentication (used by Microsoft
938 Exchange) is supported. If you compile in the support, \fIfetchmail\fR
939 will try to perform an NTLM authentication (instead of sending over the
940 password en clair) whenever the server returns AUTH=NTLM in its
941 capability response. Specify a user option value that looks like
942 \&'user@domain': the part to the left of the @ will be passed as the
943 username and the part to the right as the NTLM domain.
944 .SS Secure Socket Layers (SSL)
946 You can access SSL encrypted services by specifying the --ssl option.
947 You can also do this using the "ssl" server option in the .fetchmailrc
948 file. With SSL encryption enabled, queries are initiated over a connection
949 after negotiating an SSL session. Some services, such as POP3 and IMAP,
950 have different well known ports defined for the SSL encrypted services.
951 The encrypted ports will be selected automatically when SSL is enabled and
952 no explicit port is specified.
954 When connecting to an SSL encrypted server, the server presents a certificate
955 to the client for validation. The certificate is checked to verify that
956 the common name in the certificate matches the name of the server being
957 contacted and that the effective and expiration dates in the certificate
958 indicate that it is currently valid. If any of these checks fail, a warning
959 message is printed, but the connection continues. The server certificate
960 does not need to be signed by any specific Certifying Authority and may
961 be a "self-signed" certificate.
963 Some SSL encrypted servers may request a client side certificate. A client
964 side public SSL certificate and private SSL key may be specified. If
965 requested by the server, the client certificate is sent to the server for
966 validation. Some servers may require a valid client certificate and may
967 refuse connections if a certificate is not provided or if the certificate
968 is not valid. Some servers may require client side certificates be signed
969 by a recognized Certifying Authority. The format for the key files and
970 the certificate files is that required by the underlying SSL libraries
971 (OpenSSL in the general case).
973 A word of care about the use of SSL: While above mentioned
974 setup with self-signed server certificates retrieved over the wires
975 can protect you from a passive eavesdropper it doesn't help against an
976 active attacker. It's clearly an improvement over sending the
977 passwords in clear but you should be aware that a man-in-the-middle
978 attack is trivially possible (in particular with tools such as dsniff,
979 http://www.monkey.org/~dugsong/dsniff/). Use of an ssh tunnel (see
980 below for some examples) is preferable if you care seriously about the
981 security of your mailbox.
985 also supports authentication to the ESMTP server on the client side
986 according to RFC 2554. You can specify a name/password pair to be
987 used with the keywords 'esmtpname' and 'esmtppassword'; the former
988 defaults to the username of the calling user.
992 .B \-\-daemon <interval>
997 in daemon mode. You must specify a numeric argument which is a
998 polling interval in seconds.
1002 puts itself in background and runs forever, querying each specified
1003 host and then sleeping for the given polling interval.
1009 will, therefore, poll all the hosts described in your
1011 file (except those explicitly excluded with the 'skip' verb) once
1012 every fifteen minutes.
1014 It is possible to set a polling interval
1017 file by saying 'set daemon <interval>', where <interval> is an
1018 integer number of seconds. If you do this, fetchmail will always
1019 start in daemon mode unless you override it with the command-line
1020 option --daemon 0 or -d0.
1022 Only one daemon process is permitted per user; in daemon mode,
1024 makes a per-user lockfile to guarantee this.
1026 Normally, calling fetchmail with a daemon in the background sends a
1027 wake-up signal to the daemon, forcing it to poll mailservers
1028 immediately. (The wake-up signal is SIGHUP if fetchmail is running as
1029 root, SIGUSR1 otherwise.) The wake-up action also clears any 'wedged'
1030 flags indicating that connections have wedged due to failed
1031 authentication or multiple timeouts.
1035 will kill a running daemon process instead of waking it up (if there
1036 is no such process, \fIfetchmail\fP will notify you.
1037 If the \-\-quit option appears last on the command line, \fIfetchmail\fP
1038 will kill the running daemon process and then quit. Otherwise,
1039 \fIfetchmail\fP will first kill a running daemon process and then
1040 continue running with the other options.
1045 .B \-\-logfile <filename>
1046 option (keyword: set logfile) is only effective when fetchmail is
1047 detached. This option allows you to redirect status messages
1048 into a specified logfile (follow the option with the logfile name). The
1049 logfile is opened for append, so previous messages aren't deleted. This
1050 is primarily useful for debugging configurations.
1054 option (keyword: set syslog) allows you to redirect status and error
1055 messages emitted to the
1057 system daemon if available.
1058 Messages are logged with an id of \fBfetchmail\fR, the facility \fBLOG_MAIL\fR,
1059 and priorities \fBLOG_ERR\fR, \fBLOG_ALERT\fR or \fBLOG_INFO\fR.
1060 This option is intended for logging status and error messages which
1061 indicate the status of the daemon and the results while fetching mail
1063 Error messages for command line options and parsing the \fI.fetchmailrc\fR
1064 file are still written to stderr, or to the specified log file.
1067 option turns off use of
1069 assuming it's turned on in the
1074 .B \-\-logfile <file>
1081 option suppresses backgrounding and detachment of the
1082 daemon process from its control terminal. This is useful
1083 for debugging or when fetchmail runs as the child of a supervisor
1088 Note that this also causes the logfile option to be
1089 ignored (though perhaps it shouldn't).
1091 Note that while running in daemon mode polling a POP2 or IMAP2bis server,
1092 transient errors (such as DNS failures or sendmail delivery refusals)
1093 may force the fetchall option on for the duration of the next polling
1094 cycle. This is a robustness feature. It means that if a message is
1095 fetched (and thus marked seen by the mailserver) but not delivered
1096 locally due to some transient error, it will be re-fetched during the
1097 next poll cycle. (The IMAP logic doesn't delete messages until
1098 they're delivered, so this problem does not arise.)
1100 If you touch or change the
1102 file while fetchmail is running in daemon mode, this will be detected
1103 at the beginning of the next poll cycle. When a changed
1105 is detected, fetchmail rereads it and restarts from scratch (using
1106 exec(2); no state information is retained in the new instance). Note also
1107 that if you break the
1109 file's syntax, the new instance will softly and silently vanish away
1112 .SH ADMINISTRATIVE OPTIONS
1115 .B \-\-postmaster <name>
1116 option (keyword: set postmaster) specifies the last-resort username to
1117 which multidrop mail is to be forwarded if no matching local recipient
1118 can be found. It is also used as destination of undeliverable mail if
1119 the 'bouncemail' global option is off and additionally for spam-blocked
1120 mail if the 'bouncemail' global option is off and the 'spambounce'
1121 global option is on. This option defaults to the user who invoked
1123 If the invoking user is root, then the default of this option is
1124 the user 'postmaster'. Setting postmaster to the empty string causes
1125 such mail as described above to be discarded - this however is usually a
1127 See also the description of the 'FETCHMAILUSER' environment variable in
1128 the ENVIRONMENT section below.
1132 behaves like the "set no bouncemail" global option, which see.
1136 option (keyword: set invisible) tries to make fetchmail invisible.
1137 Normally, fetchmail behaves like any other MTA would -- it generates a
1138 Received header into each message describing its place in the chain of
1139 transmission, and tells the MTA it forwards to that the mail came from
1140 the machine fetchmail itself is running on. If the invisible option
1141 is on, the Received header is suppressed and fetchmail tries to spoof
1142 the MTA it forwards to into thinking it came directly from the
1147 option (keyword: set showdots) forces fetchmail to show progress dots
1148 even if the current tty is not stdout (for example logfiles).
1149 Starting with fetchmail version 5.3.0,
1150 progress dots are only shown on stdout by default.
1154 option, you can ask fetchmail to add information to the Received
1155 header on the form "polling {label} account {user}", where {label} is
1156 the account label (from the specified rcfile, normally ~/.fetchmailrc)
1157 and {user} is the username which is used to log on to the mail
1158 server. This header can be used to make filtering email where no
1159 useful header information is available and you want mail from
1160 different accounts sorted into different mailboxes (this could, for
1161 example, occur if you have an account on the same server running a
1162 mailing list, and are subscribed to the list using that account). The
1163 default is not adding any such header. In
1165 this is called 'tracepolls'.
1167 .SH RETRIEVAL FAILURE MODES
1168 The protocols \fIfetchmail\fR uses to talk to mailservers are next to
1169 bulletproof. In normal operation forwarding to port 25, no message is
1170 ever deleted (or even marked for deletion) on the host until the SMTP
1171 listener on the client side has acknowledged to \fIfetchmail\fR that
1172 the message has been either accepted for delivery or rejected due to a
1175 When forwarding to an MDA, however, there is more possibility
1176 of error. Some MDAs are 'safe' and reliably return a nonzero status
1177 on any delivery error, even one due to temporary resource limits.
1180 program is like this; so are most programs designed as mail transport
1185 These programs give back a reliable positive acknowledgement and
1186 can be used with the mda option with no risk of mail loss. Unsafe
1187 MDAs, though, may return 0 even on delivery failure. If this
1188 happens, you will lose mail.
1190 The normal mode of \fIfetchmail\fR is to try to download only 'new'
1191 messages, leaving untouched (and undeleted) messages you have already
1192 read directly on the server (or fetched with a previous \fIfetchmail
1193 --keep\fR). But you may find that messages you've already read on the
1194 server are being fetched (and deleted) even when you don't specify
1195 --all. There are several reasons this can happen.
1197 One could be that you're using POP2. The POP2 protocol includes no
1198 representation of 'new' or 'old' state in messages, so \fIfetchmail\fR
1199 must treat all messages as new all the time. But POP2 is obsolete, so
1202 A potential POP3 problem might be servers that insert messages
1203 in the middle of mailboxes (some VMS implementations of mail are
1204 rumored to do this). The \fIfetchmail\fR code assumes that new
1205 messages are appended to the end of the mailbox; when this is not true
1206 it may treat some old messages as new and vice versa. Using UIDL might
1207 fix this, otherwise, consider switching to IMAP.
1209 Yet another POP3 problem is that if they can't make tempfiles in the
1210 user's home directory, some POP3 servers will hand back an
1211 undocumented response that causes fetchmail to spuriously report "No
1214 The IMAP code uses the presence or absence of the server flag \eSeen
1215 to decide whether or not a message is new. This isn't the right thing
1216 to do, fetchmail should check the UIDVALIDITY and use UID, but it
1217 doesn't do that yet. Under Unix, it counts on your IMAP server to notice
1218 the BSD-style Status flags set by mail user agents and set the \eSeen
1219 flag from them when appropriate. All Unix IMAP servers we know of do
1220 this, though it's not specified by the IMAP RFCs. If you ever trip over
1221 a server that doesn't, the symptom will be that messages you have
1222 already read on your host will look new to the server. In this
1223 (unlikely) case, only messages you fetched with \fIfetchmail --keep\fR
1224 will be both undeleted and marked old.
1226 In ETRN and ODMR modes, \fIfetchmail\fR does not actually retrieve messages;
1227 instead, it asks the server's SMTP listener to start a queue flush
1228 to the client via SMTP. Therefore it sends only undelivered messages.
1231 Many SMTP listeners allow administrators to set up 'spam filters' that
1232 block unsolicited email from specified domains. A MAIL FROM or DATA line that
1233 triggers this feature will elicit an SMTP response which
1234 (unfortunately) varies according to the listener.
1238 return an error code of 571.
1240 According to RFC2821, the correct thing to return in this situation is
1241 550 "Requested action not taken: mailbox unavailable" (the draft adds
1242 "[E.g., mailbox not found, no access, or command rejected for policy
1245 Older versions of the
1247 MTA return 501 "Syntax error in parameters or arguments".
1251 MTA runs 554 as an antispam response.
1254 may reject code with a 500 response (followed by an enhanced status
1255 code that contains more information).
1259 treats as antispam responses and discards
1260 the message can be set with the 'antispam' option. This is one of the
1262 three circumstance under which fetchmail ever discards mail (the others
1263 are the 552 and 553 errors described below, and the suppression of
1264 multidropped messages with a message-ID already seen).
1268 is fetching from an IMAP server, the antispam response will be detected and
1269 the message rejected immediately after the headers have been fetched,
1270 without reading the message body. Thus, you won't pay for downloading
1271 spam message bodies.
1273 By default, the list of antispam responses is empty.
1275 If the \fIspambounce\fR global option is on, mail that is spam-blocked
1276 triggers an RFC1892/RFC1894 bounce message informing the originator that
1277 we do not accept mail from it. See also BUGS.
1279 .SH SMTP/ESMTP ERROR HANDLING
1280 Besides the spam-blocking described above, fetchmail takes special
1281 actions on the following SMTP/ESMTP error responses
1283 452 (insufficient system storage)
1284 Leave the message in the server mailbox for later retrieval.
1286 552 (message exceeds fixed maximum message size)
1287 Delete the message from the server. Send bounce-mail to the
1290 553 (invalid sending domain)
1291 Delete the message from the server. Don't even try to send
1292 bounce-mail to the originator.
1294 Other errors trigger bounce mail back to the originator. See also BUGS.
1296 .SH THE RUN CONTROL FILE
1297 The preferred way to set up fetchmail is to write a
1298 \&\fI.fetchmailrc\fR file in your home directory (you may do this
1299 directly, with a text editor, or indirectly via \fIfetchmailconf\fR).
1300 When there is a conflict between the command-line arguments and the
1301 arguments in this file, the command-line arguments take precedence.
1303 To protect the security of your passwords,
1304 your \fI~/.fetchmailrc\fR may not normally have more than 0600 (u=rw,g=,o=) permissions;
1306 will complain and exit otherwise (this check is suppressed when
1309 You may read the \fI.fetchmailrc\fR file as a list of commands to
1312 is called with no arguments.
1313 .SS Run Control Syntax
1315 Comments begin with a '#' and extend through the end of the line.
1316 Otherwise the file consists of a series of server entries or global
1317 option statements in a free-format, token-oriented syntax.
1319 There are four kinds of tokens: grammar keywords, numbers
1320 (i.e. decimal digit sequences), unquoted strings, and quoted strings.
1321 A quoted string is bounded by double quotes and may contain
1322 whitespace (and quoted digits are treated as a string). An unquoted
1323 string is any whitespace-delimited token that is neither numeric, string
1324 quoted nor contains the special characters ',', ';', ':', or '='.
1326 Any amount of whitespace separates tokens in server entries, but is
1327 otherwise ignored. You may use standard C-style escapes (\en, \et,
1328 \eb, octal, and hex) to embed non-printable characters or string
1329 delimiters in strings.
1331 Each server entry consists of one of the keywords 'poll' or 'skip',
1332 followed by a server name, followed by server options, followed by any
1333 number of user descriptions. Note: the most common cause of syntax
1334 errors is mixing up user and server options.
1336 For backward compatibility, the word 'server' is a synonym for 'poll'.
1338 You can use the noise keywords 'and', 'with',
1339 \&'has', 'wants', and 'options' anywhere in an entry to make
1340 it resemble English. They're ignored, but but can make entries much
1341 easier to read at a glance. The punctuation characters ':', ';' and
1342 \&',' are also ignored.
1345 The 'poll' verb tells fetchmail to query this host when it is run with
1346 no arguments. The 'skip' verb tells
1348 not to poll this host unless it is explicitly named on the command
1349 line. (The 'skip' verb allows you to experiment with test entries
1350 safely, or easily disable entries for hosts that are temporarily down.)
1352 .SS Keyword/Option Summary
1353 Here are the legal options. Keyword suffixes enclosed in
1354 square brackets are optional. Those corresponding to short command-line
1355 options are followed by '-' and the appropriate option letter. If
1356 option is only relevant to a single mode of operation, it is noted as
1357 's' or 'm' for singledrop- or multidrop-mode, respectively.
1359 Here are the legal global options:
1363 Keyword Opt Mode Function
1366 Set a background poll interval in seconds.
1368 set postmaster \& \& T{
1369 Give the name of the last-resort mail recipient (default: user running
1370 fetchmail, "postmaster" if run by the root user)
1372 set bouncemail \& \& T{
1373 Direct error mail to the sender (default)
1375 set no bouncemail \& \& T{
1376 Direct error mail to the local postmaster (as per the 'postmaster'
1377 global option above).
1379 set no spambounce \& \& T{
1380 Do not bounce spam-blocked mail (default).
1382 set spambounce \& \& T{
1383 Bounce blocked spam-blocked mail (as per the 'antispam' user option)
1384 back to the destination as indicated by the 'bouncemail' global option.
1385 Warning: Do not use this to bounce spam back to the sender - most spam
1386 is sent with false sender address and thus this option hurts innocent
1389 set logfile -L \& T{
1390 Name of a file to append error and status messages to.
1393 Name of the file to store UID lists in.
1396 Do error logging through syslog(3).
1398 set no syslog \& \& T{
1399 Turn off error logging through syslog(3). (default)
1401 set properties \& \& T{
1402 String value that is ignored by fetchmail (may be used by extension
1407 Here are the legal server options:
1411 Keyword Opt Mode Function
1414 Specify DNS name of mailserver, overriding poll name
1417 Specify protocol (case insensitive):
1418 POP2, POP3, IMAP, APOP, KPOP
1420 local[domains] \& m T{
1421 Specify domain(s) to be regarded as local
1424 Specify TCP/IP service port (obsolete, use 'service' instead).
1427 Specify service name (a numeric value is also allowed and
1428 considered a TCP/IP port number).
1430 auth[enticate] \& \& T{
1431 Set authentication type (default 'any')
1434 Server inactivity timeout in seconds (default 300)
1437 Specify envelope-address header name
1440 Disable looking for envelope address
1443 Qmail virtual domain prefix to remove from user name
1446 Specify alternate DNS names of mailserver
1449 specify IP interface(s) that must be up for server poll to take place
1452 Specify IP address to monitor for activity
1455 Specify command through which to make server connections.
1458 Specify command through which to make listener connections.
1461 Enable DNS lookup for multidrop (default)
1464 Disable DNS lookup for multidrop
1467 Do comparison by IP address for multidrop
1469 no checkalias \& m T{
1470 Do comparison by name for multidrop (default)
1473 Force POP3 to use client-side UIDLs (recommended)
1476 Turn off POP3 use of client-side UIDLs (default)
1479 Only check this site every N poll cycles; N is a numeric argument.
1482 Add poll tracing information to the Received header
1485 Set Kerberos principal (only useful with imap and kerberos)
1488 Set name for RFC2554 authentication to the ESMTP server.
1490 esmtppassword \& \& T{
1491 Set password for RFC2554 authentication to the ESMTP server.
1495 Here are the legal user options:
1499 Keyword Opt Mode Function
1502 Set remote user name
1503 (local user name if name followed by 'here')
1506 Connect local and remote user names
1509 Connect local and remote user names
1512 Specify remote account password
1515 Connect to server over the specified base protocol using SSL encryption
1518 Specify file for client side public SSL certificate
1521 Specify file for client side private SSL key
1524 Force ssl protocol for connection
1527 Specify remote folder to query
1530 Specify smtp host(s) to forward to
1532 fetchdomains \& m T{
1533 Specify domains for which mail should be fetched
1535 smtpaddress -D \& T{
1536 Specify the domain to be put in RCPT TO lines
1539 Specify the user and domain to be put in RCPT TO lines
1542 Specify what SMTP returns are interpreted as spam-policy blocks
1545 Specify MDA for local delivery
1548 Specify BSMTP batch file to append to
1551 Command to be executed before each connection
1553 postconnect \& \& T{
1554 Command to be executed after each connection
1557 Don't delete seen messages from server
1560 Flush all seen messages before querying (DANGEROUS)
1563 Flush all oversized messages before querying
1566 Fetch all messages whether seen or not
1569 Rewrite destination addresses for reply (default)
1572 Strip carriage returns from ends of lines
1575 Force carriage returns at ends of lines
1578 Force BODY=8BITMIME to ESMTP listener
1581 Strip Status and X-Mozilla-Status lines out of incoming mail
1583 dropdelivered \& \& T{
1584 Strip Delivered-To lines out of incoming mail
1587 Convert quoted-printable to 8-bit in MIME messages
1590 Idle waiting for new messages after each poll (IMAP only)
1593 Delete seen messages from server (default)
1596 Don't flush all seen messages before querying (default)
1598 no fetchall \& \& T{
1599 Retrieve only new messages (default)
1602 Don't rewrite headers
1605 Don't strip carriage returns (default)
1608 Don't force carriage returns at EOL (default)
1610 no pass8bits \& \& T{
1611 Don't force BODY=8BITMIME to ESMTP listener (default)
1613 no dropstatus \& \& T{
1614 Don't drop Status headers (default)
1616 no dropdelivered \& \& T{
1617 Don't drop Delivered-To headers (default)
1619 no mimedecode \& \& T{
1620 Don't convert quoted-printable to 8-bit in MIME messages (default)
1623 Don't idle waiting for new messages after each poll (IMAP only)
1626 Set message size limit
1629 Set message size warning interval
1632 Max # messages to forward in single connect
1635 Max # messages to fetch in single connect
1637 fetchsizelimit \& \& T{
1638 Max # message sizes to fetch in single transaction
1641 Use binary search for first unseen message (POP3 only)
1644 Perform an expunge on every #th message (IMAP and POP3 only)
1647 String value is ignored by fetchmail (may be used by extension scripts)
1651 Remember that all user options must \fIfollow\fR all server options.
1653 In the .fetchmailrc file, the 'envelope' string argument may be
1654 preceded by a whitespace-separated number. This number, if specified,
1655 is the number of such headers to skip over (that is, an argument of 1
1656 selects the second header of the given type). This is sometime useful
1657 for ignoring bogus envelope headers created by an ISP's local delivery
1658 agent or internal forwards (through mail inspection systems, for
1660 .SS Keywords Not Corresponding To Option Switches
1662 The 'folder' and 'smtphost' options (unlike their command-line
1663 equivalents) can take a space- or comma-separated list of names
1666 All options correspond to the obvious command-line arguments, except
1667 the following: 'via', 'interval', 'aka', 'is', 'to', 'dns'/'no dns',
1668 \&'checkalias'/'no checkalias', 'password', 'preconnect', 'postconnect',
1669 \&'localdomains', 'stripcr'/'no stripcr', 'forcecr'/'no forcecr',
1670 \&'pass8bits'/'no pass8bits' 'dropstatus/no dropstatus',
1671 \&'dropdelivered/no dropdelivered', 'mimedecode/no mimedecode', 'idle/no
1672 idle', and 'no envelope'.
1674 The 'via' option is for if you want to have more
1675 than one configuration pointing at the same site. If it is present,
1676 the string argument will be taken as the actual DNS name of the
1677 mailserver host to query.
1678 This will override the argument of poll, which can then simply be a
1679 distinct label for the configuration (e.g. what you would give on the
1680 command line to explicitly query this host).
1682 The 'interval' option (which takes a numeric argument) allows you to poll a
1683 server less frequently than the basic poll interval. If you say
1684 \&'interval N' the server this option is attached to will only be
1685 queried every N poll intervals.
1687 The 'is' or 'to' keywords associate the following local (client)
1688 name(s) (or server-name to client-name mappings separated by =) with
1689 the mailserver user name in the entry. If an is/to list has '*' as
1690 its last name, unrecognized names are simply passed through.
1692 A single local name can be used to support redirecting your mail when
1693 your username on the client machine is different from your name on the
1694 mailserver. When there is only a single local name, mail is forwarded
1695 to that local username regardless of the message's Received, To, Cc,
1696 and Bcc headers. In this case
1698 never does DNS lookups.
1700 When there is more than one local name (or name mapping) the
1701 \fIfetchmail\fR code does look at the Received, To, Cc, and Bcc
1702 headers of retrieved mail (this is 'multidrop mode'). It looks for
1703 addresses with hostname parts that match your poll name or your 'via',
1704 \&'aka' or 'localdomains' options, and usually also for hostname parts
1705 which DNS tells it are aliases of the mailserver. See the discussion
1706 of 'dns', 'checkalias', 'localdomains', and 'aka' for details on how
1707 matching addresses are handled.
1709 If \fIfetchmail\fR cannot match any mailserver usernames or
1710 localdomain addresses, the mail will be bounced.
1711 Normally it will be bounced to the sender, but if the 'bouncemail'
1712 global option is off, the mail will go to the local postmaster instead.
1713 (see the 'postmaster' global option). See also BUGS.
1715 The 'dns' option (normally on) controls the way addresses from
1716 multidrop mailboxes are checked. On, it enables logic to check each
1717 host address that doesn't match an 'aka' or 'localdomains' declaration
1718 by looking it up with DNS. When a mailserver username is recognized
1719 attached to a matching hostname part, its local mapping is added to
1720 the list of local recipients.
1722 The 'checkalias' option (normally off) extends the lookups performed
1723 by the 'dns' keyword in multidrop mode, providing a way to cope with
1724 remote MTAs that identify themselves using their canonical name, while
1725 they're polled using an alias.
1726 When such a server is polled, checks to extract the envelope address
1729 reverts to delivery using the To/Cc/Bcc headers (See below
1730 \&'Header vs. Envelope addresses').
1731 Specifying this option instructs
1733 to retrieve all the IP addresses associated with both the poll name
1734 and the name used by the remote MTA and to do a comparison of the IP
1735 addresses. This comes in handy in situations where the remote server
1736 undergoes frequent canonical name changes, that would otherwise
1737 require modifications to the rcfile. 'checkalias' has no effect if
1738 \&'no dns' is specified in the rcfile.
1740 The 'aka' option is for use with multidrop mailboxes. It allows you
1741 to pre-declare a list of DNS aliases for a server. This is an
1742 optimization hack that allows you to trade space for speed. When
1744 while processing a multidrop mailbox, grovels through message headers
1745 looking for names of the mailserver, pre-declaring common ones can
1746 save it from having to do DNS lookups. Note: the names you give
1747 as arguments to 'aka' are matched as suffixes -- if you specify
1748 (say) 'aka netaxs.com', this will match not just a hostname
1749 netaxs.com, but any hostname that ends with '.netaxs.com'; such as
1750 (say) pop3.netaxs.com and mail.netaxs.com.
1752 The 'localdomains' option allows you to declare a list of domains
1753 which fetchmail should consider local. When fetchmail is parsing
1754 address lines in multidrop modes, and a trailing segment of a host
1755 name matches a declared local domain, that address is passed through
1756 to the listener or MDA unaltered (local-name mappings are \fInot\fR
1759 If you are using 'localdomains', you may also need to specify \&'no
1760 envelope', which disables \fIfetchmail\fR's normal attempt to deduce
1761 an envelope address from the Received line or X-Envelope-To header or
1762 whatever header has been previously set by 'envelope'. If you set 'no
1763 envelope' in the defaults entry it is possible to undo that in
1764 individual entries by using 'envelope <string>'. As a special case,
1765 \&'envelope "Received"' restores the default parsing of
1768 The \fBpassword\fR option requires a string argument, which is the password
1769 to be used with the entry's server.
1771 The 'preconnect' keyword allows you to specify a shell command to be
1772 executed just before each time
1774 establishes a mailserver connection. This may be useful if you are
1775 attempting to set up secure POP connections with the aid of
1777 If the command returns a nonzero status, the poll of that mailserver
1780 Similarly, the 'postconnect' keyword similarly allows you to specify a
1781 shell command to be executed just after each time a mailserver
1782 connection is taken down.
1784 The 'forcecr' option controls whether lines terminated by LF only are
1785 given CRLF termination before forwarding. Strictly speaking RFC821
1786 requires this, but few MTAs enforce the requirement it so this option
1787 is normally off (only one such MTA, qmail, is in significant use at
1790 The 'stripcr' option controls whether carriage returns are stripped
1791 out of retrieved mail before it is forwarded. It is normally not
1792 necessary to set this, because it defaults to 'on' (CR stripping
1793 enabled) when there is an MDA declared but 'off' (CR stripping
1794 disabled) when forwarding is via SMTP. If 'stripcr' and 'forcecr' are
1795 both on, 'stripcr' will override.
1797 The 'pass8bits' option exists to cope with Microsoft mail programs that
1798 stupidly slap a "Content-Transfer-Encoding: 7bit" on everything. With
1799 this option off (the default) and such a header present,
1801 declares BODY=7BIT to an ESMTP-capable listener; this causes problems for
1802 messages actually using 8-bit ISO or KOI-8 character sets, which will
1803 be garbled by having the high bits of all characters stripped. If
1804 \&'pass8bits' is on,
1806 is forced to declare BODY=8BITMIME to any ESMTP-capable listener. If
1807 the listener is 8-bit-clean (as all the major ones now are) the right
1808 thing will probably result.
1810 The 'dropstatus' option controls whether nonempty Status and
1811 X-Mozilla-Status lines are retained in fetched mail (the default) or
1812 discarded. Retaining them allows your MUA to see what messages (if
1813 any) were marked seen on the server. On the other hand, it can
1814 confuse some new-mail notifiers, which assume that anything with a
1815 Status line in it has been seen. (Note: the empty Status lines
1816 inserted by some buggy POP servers are unconditionally discarded.)
1818 The 'dropdelivered' option controls whether Delivered-To headers will
1819 be kept in fetched mail (the default) or discarded. These headers are
1820 added by Qmail and Postfix mailservers in order to avoid mail loops but
1821 may get in your way if you try to "mirror" a mailserver within the same
1822 domain. Use with caution.
1824 The 'mimedecode' option controls whether MIME messages using the
1825 quoted-printable encoding are automatically converted into pure 8-bit
1826 data. If you are delivering mail to an ESMTP-capable, 8-bit-clean
1827 listener (that includes all of the major MTAs like sendmail), then
1828 this will automatically convert quoted-printable message headers and
1829 data into 8-bit data, making it easier to understand when reading
1830 mail. If your e-mail programs know how to deal with MIME messages,
1831 then this option is not needed. The mimedecode option is off by
1832 default, because doing RFC2047 conversion on headers throws away
1833 character-set information and can lead to bad results if the encoding
1834 of the headers differs from the body encoding.
1836 The 'idle' option is intended to be used with IMAP servers supporting
1837 the RFC2177 IDLE command extension, but does not strictly require it.
1838 If it is enabled, and fetchmail detects that IDLE is supported, an
1839 IDLE will be issued at the end of each poll. This will tell the IMAP
1840 server to hold the connection open and notify the client when new mail
1841 is available. If IDLE is not supported, fetchmail will simulate it by
1842 periodically issuing NOOP. If you need to poll a link frequently, IDLE
1843 can save bandwidth by eliminating TCP/IP connects and LOGIN/LOGOUT
1844 sequences. On the other hand, an IDLE connection will eat almost all
1845 of your fetchmail's time, because it will never drop the connection
1846 and allow other pools to occur unless the server times out the IDLE.
1847 It also doesn't work with multiple folders; only the first folder will
1851 The 'properties' option is an extension mechanism. It takes a string
1852 argument, which is ignored by fetchmail itself. The string argument may be
1853 used to store configuration information for scripts which require it.
1854 In particular, the output of '--configdump' option will make properties
1855 associated with a user entry readily available to a Python script.
1857 .SS Miscellaneous Run Control Options
1858 The words 'here' and 'there' have useful English-like
1859 significance. Normally 'user eric is esr' would mean that
1860 mail for the remote user 'eric' is to be delivered to 'esr',
1861 but you can make this clearer by saying 'user eric there is esr here',
1862 or reverse it by saying 'user esr here is eric there'
1864 Legal protocol identifiers for use with the 'protocol' keyword are:
1868 pop2 (or POP2) (legacy, to be removed from future release)
1877 Legal authentication types are 'any', 'password', 'kerberos',
1878 \&'kerberos_v4', 'kerberos_v5' and 'gssapi', 'cram-md5', 'otp', 'msn'
1879 (only for POP3), 'ntlm', 'ssh'. The 'password' type specifies
1880 authentication by normal transmission of a password (the password may be
1881 plain text or subject to protocol-specific encryption as in APOP);
1882 \&'kerberos' tells \fIfetchmail\fR to try to get a Kerberos ticket at the
1883 start of each query instead, and send an arbitrary string as the
1884 password; and 'gssapi' tells fetchmail to use GSSAPI authentication.
1885 See the description of the 'auth' keyword for more.
1887 Specifying 'kpop' sets POP3 protocol over port 1109 with Kerberos V4
1888 authentication. These defaults may be overridden by later options.
1890 There are some global option statements: 'set logfile'
1891 followed by a string sets the same global specified by --logfile. A
1892 command-line --logfile option will override this. Note that --logfile is
1893 only effective if fetchmail detaches itself from the terminal. Also,
1894 'set daemon' sets the poll interval as --daemon does. This can be
1895 overridden by a command-line --daemon option; in particular --daemon 0
1896 can be used to force foreground operation. The 'set postmaster'
1897 statement sets the address to which multidrop mail defaults if there are
1898 no local matches. Finally, 'set syslog' sends log messages to
1901 .SH INTERACTION WITH RFC 822
1902 When trying to determine the originating address of a message,
1903 fetchmail looks through headers in the following order:
1907 Resent-Sender: (ignored if it doesn't contain an @ or !)
1908 Sender: (ignored if it doesn't contain an @ or !)
1915 The originating address is used for logging, and to set the MAIL FROM
1916 address when forwarding to SMTP. This order is intended to cope
1917 gracefully with receiving mailing list messages in multidrop mode. The
1918 intent is that if a local address doesn't exist, the bounce message
1919 won't be returned blindly to the author or to the list itself, but
1920 rather to the list manager (which is less annoying).
1922 In multidrop mode, destination headers are processed as follows:
1923 First, fetchmail looks for the Received: header (or whichever one is
1924 specified by the 'envelope' option) to determine the local
1925 recipient address. If the mail is addressed to more than one recipient,
1926 the Received line won't contain any information regarding recipient addresses.
1928 Then fetchmail looks for the Resent-To:, Resent-Cc:, and Resent-Bcc:
1929 lines. If they exist, they should contain the final recipients and
1930 have precedence over their To:/Cc:/Bcc: counterparts. If the Resent-*
1931 lines don't exist, the To:, Cc:, Bcc: and Apparently-To: lines are
1932 looked for. (The presence of a Resent-To: is taken to imply that the
1933 person referred by the To: address has already received the original
1936 .SH CONFIGURATION EXAMPLES
1937 Note that although there are password declarations in a good many
1938 of the examples below, this is mainly for illustrative purposes.
1939 We recommend stashing account/password pairs in your $HOME/.netrc
1940 file, where they can be used not just by fetchmail but by ftp(1) and
1946 poll SERVERNAME protocol PROTOCOL username NAME password PASSWORD
1952 poll pop.provider.net protocol pop3 username "jsmith" password "secret1"
1955 Or, using some abbreviations:
1958 poll pop.provider.net proto pop3 user "jsmith" password "secret1"
1961 Multiple servers may be listed:
1964 poll pop.provider.net proto pop3 user "jsmith" pass "secret1"
1965 poll other.provider.net proto pop2 user "John.Smith" pass "My^Hat"
1968 Here's a version of those two with more whitespace and some noise words:
1971 poll pop.provider.net proto pop3
1972 user "jsmith", with password secret1, is "jsmith" here;
1973 poll other.provider.net proto pop2:
1974 user "John.Smith", with password "My^Hat", is "John.Smith" here;
1977 This version is much easier to read and doesn't cost significantly
1978 more (parsing is done only once, at startup time).
1981 If you need to include whitespace in a parameter string, enclose the
1982 string in double quotes. Thus:
1985 poll mail.provider.net with proto pop3:
1986 user "jsmith" there has password "u can't krak this"
1987 is jws here and wants mda "/bin/mail"
1990 You may have an initial server description headed by the keyword
1991 \&'defaults' instead of 'poll' followed by a name. Such a record
1992 is interpreted as defaults for all queries to use. It may be overwritten
1993 by individual server descriptions. So, you could write:
1998 poll pop.provider.net
2000 poll mail.provider.net
2001 user "jjsmith" there has password "secret2"
2004 It's possible to specify more than one user per server (this is only
2005 likely to be useful when running fetchmail in daemon mode as root).
2006 The 'user' keyword leads off a user description, and every user specification
2007 in a multi-user entry must include it. Here's an example:
2010 poll pop.provider.net proto pop3 port 3111
2011 user "jsmith" with pass "secret1" is "smith" here
2012 user jones with pass "secret2" is "jjones" here keep
2015 This associates the local username 'smith' with the pop.provider.net
2016 username 'jsmith' and the local username 'jjones' with the
2017 pop.provider.net username 'jones'. Mail for 'jones' is kept on the
2018 server after download.
2020 Here's what a simple retrieval configuration for a multi-drop mailbox
2024 poll pop.provider.net:
2025 user maildrop with pass secret1 to golux 'hurkle'='happy' snark here
2028 This says that the mailbox of account 'maildrop' on the server is a
2029 multi-drop box, and that messages in it should be parsed for the
2030 server user names 'golux', 'hurkle', and 'snark'. It further
2031 specifies that 'golux' and 'snark' have the same name on the
2032 client as on the server, but mail for server user 'hurkle' should be
2033 delivered to client user 'happy'.
2035 Here's an example of another kind of multidrop connection:
2038 poll pop.provider.net localdomains loonytoons.org toons.org:
2039 user maildrop with pass secret1 to * here
2042 This also says that the mailbox of account 'maildrop' on the server is
2043 a multi-drop box. It tells fetchmail that any address in the
2044 loonytoons.org or toons.org domains (including sub-domain addresses like
2045 \&'joe@daffy.loonytoons.org') should be passed through to the local SMTP
2046 listener without modification. Be careful of mail loops if you do this!
2048 Here's an example configuration using ssh and the plugin option. The
2049 queries are made directly on the stdin and stdout of imapd via ssh.
2050 Note that in this setup, IMAP authentication can be skipped.
2053 poll mailhost.net with proto imap:
2054 plugin "ssh %h /usr/sbin/imapd" auth ssh;
2055 user esr is esr here
2058 .SH THE USE AND ABUSE OF MULTIDROP MAILBOXES
2059 Use the multiple-local-recipients feature with caution -- it can bite.
2060 All multidrop features are ineffective in ETRN and ODMR modes.
2062 Also, note that in multidrop mode duplicate mails are suppressed. A
2063 piece of mail is considered duplicate if it has the same message-ID as
2064 the message immediately preceding and more than one addressee. Such
2065 runs of messages may be generated when copies of a message addressed
2066 to multiple users are delivered to a multidrop box.
2068 .SS Header vs. Envelope addresses
2069 The fundamental problem is that by having your mailserver toss several
2070 peoples' mail in a single maildrop box, you may have thrown away
2071 potentially vital information about who each piece of mail was
2072 actually addressed to (the 'envelope address', as opposed to the
2073 header addresses in the RFC822 To/Cc headers - the Bcc is not available
2074 at the receiving end). This 'envelope address' is the address you need
2075 in order to reroute mail properly.
2079 can deduce the envelope address. If the mailserver MTA is
2081 and the item of mail had just one recipient, the MTA will have written
2082 a 'by/for' clause that gives the envelope addressee into its Received
2083 header. But this doesn't work reliably for other MTAs, nor if there is
2084 more than one recipient. By default, \fIfetchmail\fR looks for
2085 envelope addresses in these lines; you can restore this default with
2086 -E "Received" or \&'envelope Received'.
2088 .B As a better alternative,
2089 some SMTP listeners and/or mail servers insert a header
2090 in each message containing a copy of the envelope addresses. This
2091 header (when it exists) is often 'X-Original-To', 'Delivered-To' or
2092 'X-Envelope-To'. Fetchmail's assumption about this can be changed with
2093 the -E or 'envelope' option. Note that writing an envelope header of
2094 this kind exposes the names of recipients (including blind-copy
2095 recipients) to all receivers of the messages, so the upstream must store
2096 one copy of the message per recipient to avoid becoming a privacy problem.
2098 Postfix, since version 2.0, writes an X-Original-To: header which
2099 contains a copy of the envelope as it was received.
2101 Qmail and Postfix generally write a 'Delivered-To' header upon
2102 delivering the message to the mail spool and use it to avoid mail loops.
2103 Qmail virtual domains however will prefix the user name with a string
2104 that normally matches the user's domain. To remove this prefix you can
2105 use the -Q or 'qvirtual' option.
2107 Sometimes, unfortunately, neither of these methods works. That is the
2108 point when you should contact your ISP and ask them to provide such an
2109 envelope header, and you should not use multidrop in this situation.
2110 When they all fail, fetchmail must fall back on the contents of To/Cc
2111 headers (Bcc headers are not available - see below) to try to determine
2112 recipient addressees -- and these are unreliable.
2113 In particular, mailing-list software often ships mail with only
2114 the list broadcast address in the To header.
2116 .B Note that a future version of fetchmail may remove To/Cc parsing!
2120 cannot deduce a recipient address that is local, and the intended
2121 recipient address was anyone other than fetchmail's invoking user,
2122 .B mail will get lost.
2123 This is what makes the multidrop feature risky without proper envelope
2126 A related problem is that when you blind-copy a mail message, the Bcc
2127 information is carried \fIonly\fR as envelope address (it's removed from
2128 the headers by the sending mail server, so fetchmail can see it only if
2129 there is an X-Envelope-To header). Thus, blind-copying to someone who
2130 gets mail over a fetchmail multidrop link will fail unless the the
2131 mailserver host routinely writes X-Envelope-To or an equivalent header
2132 into messages in your maildrop.
2134 \fBIn conclusion, mailing lists and Bcc'd mail can only work if the
2135 server you're fetching from (1) stores one copy of the message per
2136 recipient in \fBIyour\fP domain and (2) records the envelope
2137 information in a special header (X-Original-To, Delivered-To,
2140 .SS Good Ways To Use Multidrop Mailboxes
2141 Multiple local names can be used to administer a mailing list from the
2142 client side of a \fIfetchmail\fR collection. Suppose your name is
2143 \&'esr', and you want to both pick up your own mail and maintain a mailing
2144 list called (say) "fetchmail-friends", and you want to keep the alias
2145 list on your client machine.
2147 On your server, you can alias \&'fetchmail-friends' to 'esr'; then, in
2148 your \fI.fetchmailrc\fR, declare \&'to esr fetchmail-friends here'.
2149 Then, when mail including 'fetchmail-friends' as a local address
2150 gets fetched, the list name will be appended to the list of
2151 recipients your SMTP listener sees. Therefore it will undergo alias
2152 expansion locally. Be sure to include 'esr' in the local alias
2153 expansion of fetchmail-friends, or you'll never see mail sent only to
2154 the list. Also be sure that your listener has the "me-too" option set
2155 (sendmail's -oXm command-line option or OXm declaration) so your name
2156 isn't removed from alias expansions in messages you send.
2158 This trick is not without its problems, however. You'll begin to see
2159 this when a message comes in that is addressed only to a mailing list
2160 you do \fInot\fR have declared as a local name. Each such message
2161 will feature an 'X-Fetchmail-Warning' header which is generated
2162 because fetchmail cannot find a valid local name in the recipient
2163 addresses. Such messages default (as was described above) to being
2164 sent to the local user running
2166 but the program has no way to know that that's actually the right thing.
2168 .SS Bad Ways To Abuse Multidrop Mailboxes
2169 Multidrop mailboxes and
2171 serving multiple users in daemon mode do not mix. The problem, again, is
2172 mail from mailing lists, which typically does not have an individual
2173 recipient address on it. Unless
2175 can deduce an envelope address, such mail will only go to the account
2176 running fetchmail (probably root). Also, blind-copied users are very
2177 likely never to see their mail at all.
2179 If you're tempted to use
2181 to retrieve mail for multiple users from a single mail drop via POP or
2182 IMAP, think again (and reread the section on header and envelope
2183 addresses above). It would be smarter to just let the mail sit in the
2184 mailserver's queue and use fetchmail's ETRN or ODMR modes to trigger
2185 SMTP sends periodically (of course, this means you have to poll more
2186 frequently than the mailserver's expiry period). If you can't arrange
2187 this, try setting up a UUCP feed.
2189 If you absolutely \fImust\fR use multidrop for this purpose, make sure
2190 your mailserver writes an envelope-address header that fetchmail can
2191 see. Otherwise you \fIwill\fR lose mail and it \fIwill\fR come back
2194 .SS Speeding Up Multidrop Checking
2195 Normally, when multiple users are declared
2197 extracts recipient addresses as described above and checks each host
2198 part with DNS to see if it's an alias of the mailserver. If so, the
2199 name mappings described in the "to ... here" declaration are done and
2200 the mail locally delivered.
2202 This is a convenient but also slow method. To speed
2203 it up, pre-declare mailserver aliases with 'aka'; these are checked
2204 before DNS lookups are done. If you're certain your aka list contains
2206 DNS aliases of the mailserver (and all MX names pointing at it - note
2207 this may change in a future version)
2208 you can declare 'no dns' to suppress DNS lookups entirely and
2209 \fIonly\fR match against the aka list.
2212 To facilitate the use of
2214 in shell scripts, an exit code is returned to give an indication
2215 of what occurred during a given connection.
2217 The exit codes returned by
2221 One or more messages were successfully retrieved (or, if the -c option
2222 was selected, were found waiting but not retrieved).
2224 There was no mail awaiting retrieval. (There may have been old mail still
2225 on the server but not selected for retrieval.)
2227 An error was encountered when attempting to open a socket to retrieve
2228 mail. If you don't know what a socket is, don't worry about it --
2229 just treat this as an 'unrecoverable error'. This error can also be
2230 because a protocol fetchmail wants to use is not listed in /etc/services.
2232 The user authentication step failed. This usually means that a bad
2233 user-id, password, or APOP id was specified. Or it may mean that you
2234 tried to run fetchmail under circumstances where it did not have
2235 standard input attached to a terminal and could not prompt for a
2238 Some sort of fatal protocol error was detected.
2240 There was a syntax error in the arguments to
2243 The run control file had bad permissions.
2245 There was an error condition reported by the server. Can also
2248 timed out while waiting for the server.
2250 Client-side exclusion error. This means
2252 either found another copy of itself already running, or failed in such
2253 a way that it isn't sure whether another copy is running.
2255 The user authentication step failed because the server responded "lock
2256 busy". Try again after a brief pause! This error is not implemented
2257 for all protocols, nor for all servers. If not implemented for your
2258 server, "3" will be returned instead, see above. May be returned when
2259 talking to qpopper or other servers that can respond with "lock busy"
2260 or some similar text containing the word "lock".
2264 run failed while trying to do an SMTP port open or transaction.
2266 Fatal DNS error. Fetchmail encountered an error while performing
2267 a DNS lookup at startup and could not proceed.
2269 BSMTP batch file could not be opened.
2271 Poll terminated by a fetch limit (see the --fetchlimit option).
2273 Server busy indication.
2275 Server timed out during an IMAP IDLE.
2277 Internal error. You should see a message on standard error with
2282 queries more than one host, return status is 0 if \fIany\fR query
2283 successfully retrieved mail. Otherwise the returned error status is
2284 that of the last host queried.
2289 default run control file
2292 default location of file associating hosts with last message IDs seen
2293 (used only with newer RFC1939-compliant POP3 servers supporting the
2297 lock file to help prevent concurrent runs (non-root mode).
2300 your FTP run control file, which (if present) will be searched for
2301 passwords as a last resort before prompting for one interactively.
2303 /var/run/fetchmail.pid
2304 lock file to help prevent concurrent runs (root mode, Linux systems).
2307 lock file to help prevent concurrent runs (root mode, systems without /var/run).
2310 If the FETCHMAILUSER variable is set, it is used as the name of the
2311 calling user (default local name) for purposes such as mailing error
2312 notifications. Otherwise, if either the LOGNAME or USER variable is
2313 correctly set (e.g. the corresponding UID matches the session user ID)
2314 then that name is used as the default local name. Otherwise
2315 \fBgetpwuid\fR(3) must be able to retrieve a password entry for the
2316 session ID (this elaborate logic is designed to handle the case of
2317 multiple names per userid gracefully).
2319 If the environment variable FETCHMAILHOME is set to a valid and
2320 existing directory name, the .fetchmailrc and .fetchids and
2321 \&.fetchmail.pid files are put there instead of in the invoking user's
2322 home directory (and lose the leading dots on their names). The
2323 \&.netrc file is looked for in the the invoking user's home directory
2324 regardless of FETCHMAILHOME's setting.
2326 If the HOME_ETC variable is set, file $HOME_ETC/.fetchmailrc is used
2327 instead of ~/.fetchmailrc.
2332 daemon is running as root, SIGHUP wakes it up from its sleep phase and
2333 forces a poll of all non-skipped servers (this is in accordance with
2334 the usual conventions for system daemons).
2338 is running in daemon mode as non-root, use SIGUSR1 to wake it (this is
2339 so SIGHUP due to logout can retain the default action of killing it).
2343 in foreground while a background fetchmail is running will do
2344 whichever of these is appropriate to wake it up.
2346 .SH BUGS AND KNOWN PROBLEMS
2348 The assumptions that the DNS and in particular the checkalias options
2349 make are not often sustainable. For instance, it has become uncommon for
2350 an MX server to be a POP3 or IMAP server at the same time. Therefore the
2351 MX lookups may go away in a future release.
2353 The mda and plugin options interact badly. In order to collect error
2354 status from the MDA, fetchmail has to change its normal signal
2355 handling so that dead plugin processes don't get reaped until the end
2356 of the poll cycle. This can cause resource starvation if too many
2357 zombies accumulate. So either don't deliver to a MDA using plugins or
2358 risk being overrun by an army of undead.
2360 The --interface option does not support IPv6 and it is doubtful if it
2361 ever will, since there is no portable way to query interface IPv6
2364 The RFC822 address parser used in multidrop mode chokes on some
2365 @-addresses that are technically legal but bizarre. Strange uses of
2366 quoting and embedded comments are likely to confuse it.
2368 In a message with multiple envelope headers, only the last one
2369 processed will be visible to fetchmail. To get around this, use a
2370 mailserver-side filter that consolidates the contents of all envelope
2371 headers into a single one (procmail, mailagent, or maildrop can be
2372 programmed to do this fairly easily).
2374 Use of some of these protocols requires that the program send
2375 unencrypted passwords over the TCP/IP connection to the mailserver.
2376 This creates a risk that name/password pairs might be snaffled with a
2377 packet sniffer or more sophisticated monitoring software. Under Linux
2378 and FreeBSD, the --interface option can be used to restrict polling to
2379 availability of a specific interface device with a specific local or
2380 remote IP address, but snooping is still possible if (a) either host
2381 has a network device that can be opened in promiscuous mode, or (b)
2382 the intervening network link can be tapped. We recommend the use of
2384 tunnelling to not only shroud your passwords but encrypt the entire
2387 Use of the %F or %T escapes in an mda option could open a security
2388 hole, because they pass text manipulable by an attacker to a shell
2389 command. Potential shell characters are replaced by '_' before
2390 execution. The hole is further reduced by the fact that fetchmail
2391 temporarily discards any suid privileges it may have while running the
2392 MDA. For maximum safety, however, don't use an mda command containing
2393 %F or %T when fetchmail is run from the root account itself.
2395 Fetchmail's method of sending bounces due to errors or spam-blocking and
2396 spam bounces requires that port 25 of localhost be available for sending
2401 while a background instance is running and break the syntax, the
2402 background instance will die silently. Unfortunately, it can't
2403 die noisily because we don't yet know whether syslog should be enabled.
2404 On some systems, fetchmail dies quietly even if there is no syntax
2405 error; this seems to have something to do with buggy terminal ioctl
2408 The -f - option (reading a configuration from stdin) is incompatible
2409 with the plugin option.
2411 The 'principal' option only handles Kerberos IV, not V.
2413 Send comments, bug reports, gripes, and the like to the
2414 fetchmail-devel list <fetchmail-devel@lists.berlios.de>. An HTML FAQ is
2415 available at the fetchmail home page; surf to
2416 http://fetchmail.berlios.de/ or do a WWW search for pages with
2417 \&'fetchmail' in their titles.
2420 Eric S. Raymond <esr@snark.thyrsus.com>. Too many other people to
2421 name here have contributed code and patches.
2422 This program is descended from and replaces
2424 by Carl Harris <ceharris@mal.com>; the internals have become quite different,
2425 but some of its interface design is directly traceable to that
2428 This manual page has been improved by R.\ Hannes Beinert.
2430 Fetchmail is currently maintained by Matthias Andree and Rob Funk.
2433 mutt(1), elm(1), mail(1), sendmail(8), popd(8), imapd(8), netrc(5)
2434 .SH APPLICABLE STANDARDS
2437 RFC 821, RFC2821, RFC 1869, RFC 1652, RFC 1870, RFC 1983, RFC 1985,
2441 RFC 822, RFC2822, RFC 1123, RFC 1892, RFC 1894.
2447 RFC 1081, RFC 1225, RFC 1460, RFC 1725, RFC1734, RFC 1939, RFC 1957,
2451 RFC 1460, RFC 1725, RFC 1939.
2460 RFC 1730, RFC 1731, RFC 1732, RFC 2060, RFC 2061, RFC 2195, RFC 2177,
projects / ~andy / fetchmail / blob