2 .\" ** The above line should force tbl to be used as a preprocessor **
4 .\" Man page for fetchmail
6 .\" For license terms, see the file COPYING in this directory.
9 fetchmail \- fetch mail from a POP, IMAP, or ETRN-capable server
12 \fBfetchmail\fR [\fIoptions\fR] [\fImailserver...\fR]
18 is a mail-retrieval and forwarding utility; it fetches
19 mail from remote mailservers and forwards it to your local (client)
20 machine's delivery system. You can then handle the retrieved mail
21 using normal mail user agents such as \fIelm\fR(1) or \fIMail\fR(1).
22 The \fBfetchmail\fR utility can be run in a daemon mode to repeatedly
23 poll one or more systems at a specified interval.
27 program can gather mail from servers supporting any of the common
28 mail-retrieval protocols: POP2, POP3, IMAP2bis, and IMAP4. It can
29 also use the ESMTP ETRN extension. (The RFCs describing all these
30 protocols are listed at the end of this document.)
34 is primarily intended to be used over on-demand TCP/IP links (such as
35 SLIP or PPP connections), it may also be useful as a message transfer
36 agent for sites which refuse for security reasons to permit
37 (sender-initiated) SMTP transactions with sendmail.
39 As each message is retrieved \fIfetchmail\fR normally delivers it via SMTP to
40 port 25 on the machine it is running on (localhost), just as though it
41 were being passed in over a normal TCP/IP link. The mail will then be
42 delivered locally via your system's MDA (Mail Delivery Agent, usually
43 \fIsendmail\fR(8) but your system may use a different one such
44 as \fIsmail\fR, \fImmdf\fR, or \fIqmail\fR). All the delivery-control
45 mechanisms (such as \fI.forward\fR files) normally available through
46 your system MDA and local delivery agents will therefore work.
50 is available, it will assist you in setting up and editing a
51 fetchmailrc configuration. It runs under X and requires that the
52 language Python and the Tk toolkit be present on your system. If
53 you are first setting up fetchmail for single-user mode, it is
54 recommended that you use Novice mode. Expert mode provides
55 complete control of fetchmail configuration, including the
61 is controlled by command-line options and a run control file,
62 .IR ~/.fetchmailrc\fR ,
63 the syntax of which we describe in a later section (this file is what
64 the \fIfetchmailconf\fR program edits). Command-line options override
68 Each server name that you specify following the options on the
69 command line will be queried. If you don't specify any servers
70 on the command line, each server in your
74 To facilitate the use of
76 In scripts, pipelines, etc., it returns an appropriate exit code upon
77 termination -- see EXIT CODES below.
78 The following options modify the behavior of \fIfetchmail\fR. It is
79 seldom necessary to specify any of these once you have a
80 working \fI.fetchmailrc\fR file set up.
82 Almost all options have a corresponding keyword which can be used to
87 Some special options are not covered here, but are documented insttead
88 in sections on AUTHENTICATION and DAEMON MODE which follows.
92 Displays the version information for your copy of
94 No mail fetch is performed.
95 Instead, for each server specified, all option information
96 that would be computed if
98 were connecting to that server is displayed. Any non-printables in
99 passwords or other string names are shown as backslashed C-like
100 escape sequences. This option is useful for verifying that your
101 options are set the way you want them.
104 Return a status code to indicate whether there is mail waiting,
105 without actually fetching or deleting mail (see EXIT CODES below).
106 This option turns off daemon mode (in which it would be useless). It
107 doesn't play well with queries to multiple sites, and doesn't work
108 with ETRN. It will return a false positive if you leave read but
109 undeleted mail in your server mailbox and your fetch protocol can't
110 tell kept messages from new ones. This means it will work with IMAP,
111 not work with POP2, and may occasionally flake out under POP3.
114 Silent mode. Suppresses all progress/status messages that are
115 normally echoed to standard error during a fetch (but does not
116 suppress actual error messages). The --verbose option overrides this.
119 Verbose mode. All control messages passed between
121 and the mailserver are echoed to stderr. Overrides --silent.
126 Retrieve both old (seen) and new messages from the mailserver. The
127 default is to fetch only messages the server has not marked seen.
128 Under POP3, this option also forces the use of RETR rather than TOP.
129 Note that POP2 retrieval behaves as though --all is always on (see
130 RETRIEVAL FAILURE MODES below) and this option does not work with ETRN.
134 Keep retrieved messages on the remote mailserver. Normally, messages
135 are deleted from the folder on the mailserver after they have been retrieved.
138 option causes retrieved messages to remain in your folder on the
139 mailserver. This option does not work with ETRN.
143 Delete retrieved messages from the remote mailserver. This
144 option forces retrieved mail to be deleted. It may be useful if
145 you have specified a default of \fBkeep\fR in your
146 \&\fI.fetchmailrc\fR. This option is forced on with ETRN.
149 POP3/IMAP only. Delete old (previously retrieved) messages from the mailserver
150 before retrieving new messages. This option does not work with ETRN.
151 Warning: if your local MTA hangs and fetchmail is aborted, the next
152 time you run fetchmail, it will delete mail that was never delivered to you.
153 What you probably want is the default setting: if you don't specify `-k', then
154 fetchmail will automatically delete messages after successful delivery.
155 .SS Protocol and Query Options
157 .B \-p, \--protocol proto
158 (Keyword: proto[col])
159 Specify the protocol to used when communicating with the remote
160 mailserver. If no protocol is specified,
162 will try each of the supported protocols in turn, terminating after
163 any successful attempt.
165 may be one of the following:
168 Post Office Protocol 2
170 Post Office Protocol 3
172 Use POP3 with MD5 authentication.
174 Use POP3 with RPOP authentication.
176 Use POP3 with Kerberos V4 authentication on port 1109.
178 IMAP2bis, IMAP4, or IMAP4rev1 (\fIfetchmail\fR autodetects their capabilities).
180 IMAP4, or IMAP4rev1 (\fIfetchmail\fR autodetects their capabilities)
181 with RFC 1731 Kerberos v4 authentication.
183 IMAP4, or IMAP4rev1 (\fIfetchmail\fR autodetects their capabilities)
184 with RFC 1731 GSSAPI authentication.
186 Use the ESMTP ETRN option.
188 All these alternatives work in basically the same way (communicating
189 with standard server daemons to fetch mail already delivered to a
190 mailbox on the server) except ETRN. The ETRN mode allows you to ask a
191 compliant ESMTP server (such as BSD sendmail at release 8.8.0 or
192 higher) to immediately open a sender-SMTP connection to your
193 client machine and begin forwarding any items addressed to your client
194 machine in the server's queue of undelivered mail.
198 Force UIDL use (effective only with POP3). Force client-side tracking
199 of `newness' of messages (UIDL stands for ``unique ID listing'' and is
200 described in RFC1725). Use with `keep' to use a mailbox as a baby
201 news drop for a group of users.
205 The option permits you to specify a TCP/IP port to connect on.
206 This option will seldom be necessary as all the supported protocols have
207 well-established default port numbers.
209 .B \-r folder, --folder folder
211 Causes a specified non-default mail folder on the mailserver (or
212 comma-separated list of folders) to be retrieved. The syntax of the
213 folder name is server-dependent. This option is not available under
215 .SS Delivery Control Options
217 .B \-S host, --smtphost host
218 (Keyword: smtp[host])
219 Specify a hunt list of hosts to forward mail to (one or more
220 hostnames, comma-separated). In ETRN mode, set the host that the
221 mailserver is asked to ship mail to. Hosts are tried in list order;
222 the first one that is up becomes the forwarding or ETRN target for the
223 current run. In all modes except ETRN, `localhost' is added to the
224 end of the list as an invisible default. Each hostname may have a
225 '/'-delimited suffix specifying a port or service to forward to; the
226 default is 25 (or "smtp" under IPv6).
228 .B \-D domain, --smtpaddress domain
229 (Keyword: smtpaddress)
230 Specify the domain to be put in RCPT TO lines shipped to SMTP. The
231 name of the SMTP server (as specified by --smtphost, or defaulted to
232 "localhost") is used when this is not specified.
234 .B \-Z nnn, --antispam nnn
236 Specifies the numeric SMTP error that is to be interpreted as a
237 spam-block response from the listener. A value of -1 disables
242 You can force mail to be passed to an MDA directly (rather than
243 forwarded to port 25) with the -mda or -m option. If \fIfetchmail\fR
244 is running as root, it sets its userid to that of the target user
245 while delivering mail through an MDA. Some possible MDAs are
246 "/usr/sbin/sendmail -oem", "/usr/lib/sendmail -oem",
247 "/usr/bin/formail", and "/usr/bin/deliver". Local delivery addresses
248 will be inserted into the MDA command wherever you place a %T; the
249 mail message's From address will be inserted where you place an %F. Do
250 \fInot\fR use an MDA invocation like
251 "sendmail -oem -t" that dispatches on the contents of To/Cc/Bcc, it
252 will create mail loops and bring the just wrath of many postmasters
254 .SS Resource Limit Control Options
258 Takes a maximum octet size argument. Messages larger than this size
259 will not be fetched, not be marked seen, and will be left on the
260 server (in foreground sessions, the progress messages will note that
261 they are "oversized"). An explicit --limit of 0 overrides any limits set
262 in your run control file. This option is intended for those needing to
263 strictly control fetch time in interactive mode. It may not be used
264 with daemon mode, as users would never receive a notification that
265 messages were waiting. This option does not work with ETRN.
268 (Keyword: batchlimit)
269 Specify the maximum number of messages that will be shipped to an SMTP
270 listener before the connection is deliberately torn down and rebuilt
271 (defaults to 0, meaning no limit). An explicit --batchlimit of 0
272 overrides any limits set in your run control file. While
273 \fBsendmail\fR(8) normally initiates delivery of a message immediately
274 after receiving the message terminator, some SMTP listeners are not so
275 prompt. MTAs like \fIqmail\fR(8) and \fIsmail\fR(8) may wait till the
276 delivery socket is shut down to deliver. This may produce annoying
279 is processing very large batches. Setting the batch limit to some
280 nonzero size will prevent these delays.
281 This option does not work with ETRN.
284 (Keyword: fetchlimit)
285 Limit the number of messages accepted from a given server in a single
286 poll. By default there is no limit. An explicit --fetchlimit of 0
287 overrides any limits set in your run control file.
288 This option does not work with ETRN.
292 When talking to an IMAP server,
294 normally issues an EXPUNGE command after each deletion in order to
295 force the deletion to be done immediately. This is safest when your
296 connection to the server is flaky and expensive, as it avoids
297 resending duplicate mail after a line hit. However, on large
298 mailboxes the overhead of re-indexing after every message can slam the
299 server pretty hard, so if your connection is reliable it is good to do
300 expunges less frequently. If you specify this option to an integer N,
303 to only issue expunges on every Nth delete. An argument
304 of zero suppresses expunges entirely (so no expunges at all will be
305 done until the end of run).
306 This option does not work with ETRN, POP2, or POP3.
307 .SS Authentication Options
309 .B \-u name, --username name
310 (Keyword: user[name])
311 Specifies the user identification to be used when logging in to the mailserver.
312 The appropriate user identification is both server and user-dependent.
313 The default is your login name on the client machine that is running
315 See USER AUTHENTICATION below for a complete description.
317 .B \-I specification, --interface specification
319 Require that a specific interface device be up and have a specific local
320 IP address (or range) before polling. Frequently
322 is used over a transient point-to-point TCP/IP link established directly
323 to a mailserver via SLIP or PPP. That is a relatively secure channel.
324 But when other TCP/IP routes to the mailserver exist (e.g. when the link
325 is connected to an alternate ISP), your username and password may be
326 vulnerable to snooping (especially when daemon mode automatically polls
327 for mail, shipping a clear password over the net at predictable
328 intervals). The --interface option may be used to prevent this. When
329 the specified link is not up or is not connected to a matching IP
330 address, polling will be skipped. The format is:
332 interface/iii.iii.iii.iii/mmm.mmm.mmm.mmm
334 The field before the first slash is the interface name (i.e. sl0, ppp0
335 etc.). The field before the second slash is the acceptable IP address.
336 The field after the second slash is a mask which specifies a range of
337 IP addresses to accept. If no mask is present 255.255.255.255 is
338 assumed (i.e. an exact match). This option is currently only supported
341 .B \-M interface, --monitor interface
343 Daemon mode can cause transient links which are automatically taken down
344 after a period of inactivity (e.g. PPP links) to remain up
345 indefinitely. This option identifies a system TCP/IP interface to be
346 monitored for activity. After each poll interval, if the link is up but
347 no other activity has occurred on the link, then the poll will be
348 skipped. This option is currently only supported under Linux.
351 (Keyword: auth[enticate])
352 This option permits you to specify a preauthentication type (see USER
353 AUTHENTICATION below for details). The possible values are
354 \&`\fBpassword\fR', `\fBkerberos_v5\fR' and `\fBkerberos\fR' (or, for
355 excruciating exactness, `\fBkerberos_v4\fR'). This option is provided
356 primarily for developers; choosing KPOP protocol automatically selects
357 Kerberos preauthentication, and all other alternatives use password
358 authentication (though APOP uses a generated one-time key as the
359 password and IMAP-K4 uses RFC1731 Kerberos v4 authentication). This
360 option does not work with ETRN.
361 .SS Miscellaneous Options
363 .B \-f pathname, --fetchmailrc pathname
364 Specify a non-default name for the
366 run control file. Unless the --version option is also on, the file must have
367 permissions no more open than 0600 (u=rw,g=,o=) or else be /dev/null.
369 .B \-i pathname, --idfile pathname
371 Specify an alternate name for the .fetchids file used to save POP3
375 (Keyword: no rewrite)
378 edits RFC-822 address headers (To, From, Cc, Bcc, and Reply-To) in
379 fetched mail so that any mail IDs local to the server are expanded to
380 full addresses (@ and the mailserver hostname are appended). This enables
381 replies on the client to get addressed correctly (otherwise your
382 mailer might think they should be addressed to local users on the
383 client machine!). This option disables the rewrite. (This option is
384 provided to pacify people who are paranoid about having an MTA edit
385 mail headers and want to know they can prevent it, but it is generally
386 not a good idea to actually turn off rewrite.)
387 When using ETRN, the rewrite option is ineffective.
391 This option changes the header
393 assumes will carry a copy of the mail's envelope address. Normally
394 this is `X-Envelope-To' but as this header is not standard, practice
395 varies. See the discussion of multidrop address handling below. As a
396 special case, `envelope "Received"' enables parsing of sendmail-style
397 Received lines. This is the default, and it should not be necessary
398 unless you have globally disabled Received parsing with `no envelope'
399 in the \fI.fetchmailrc\fR file.
403 The string prefix assigned to this option will be removed from the user
404 name found in the header specified with the \fIenvelope\fR option
405 (\fIbefore\fR doing multidrop name mapping or localdomain checking,
406 if either is applicable). This option is useful if you are using
408 to collect the mail for an entire domain and your ISP (or your mail
409 redirection provider) is using qmail.
410 One of the basic features of qmail is the
414 message header. Whenever qmail delivers a message to a local mailbox
415 it puts the username and hostname of the envelope recipient on this
416 line. The major reason for this is to prevent mail loops. To set up
417 qmail to batch mail for a disconnected site the ISP-mailhost will have
418 normally put that site in its `Virtualhosts' control file so it will
419 add a prefix to all mail addresses for this site. This results in mail
420 sent to 'username@userhost.userdom.dom.com' having a
421 \&`Delivered-To:' line of the form:
423 Delivered-To: mbox-userstr-username@userhost.userdom.dom.com
425 The ISP can make the 'mbox-userstr-' prefix anything they choose
426 but a string matching the user host name is likely.
427 By using the option `envelope Delivered-To:' you can make fetchmail reliably
428 identify the original envelope recipient, but you have to strip the
429 `mbox-userstr-' prefix to deliver to the correct user.
430 This is what this option is for.
435 file, interpret any command-line options specified, and dump a
436 configuration report to standard output. The configuration report is
437 a data structure assignment in the language Python. This option
438 is meant to be used with an interactive
440 editor written in Python.
442 .SH USER AUTHENTICATION AND ENCRYPTION
443 Every mode except ETRN requires authentication of the client.
444 Normal user authentication in
446 is very much like the authentication mechanism of
448 The correct user-id and password depend upon the underlying security
449 system at the mailserver.
451 If the mailserver is a Unix machine on which you have an ordinary user
452 account, your regular login name and password are used with
454 If you use the same login name on both the server and the client machines,
455 you needn't worry about specifying a user-id with the
458 the default behavior is to use your login name on the client machine as the
459 user-id on the server machine. If you use a different login name
460 on the server machine, specify that login name with the
462 option. e.g. if your login name is 'jsmith' on a machine named 'mailgrunt',
467 fetchmail -u jsmith mailgrunt
469 The default behavior of
471 is to prompt you for your mailserver password before the connection is
472 established. This is the safest way to use
474 and ensures that your password will not be compromised. You may also specify
475 your password in your
477 file. This is convenient when using
479 in daemon mode or with scripts.
481 If you do not specify a password, and
483 cannot extract one from your
485 file, it will look for a
487 file in your home directory before requesting one interactively; if an
488 entry matching the mailserver is found in that file, the password will
491 man page for details of the syntax of the
493 file. (This feature may allow you to avoid duplicating password
494 information in more than one file.)
496 On mailservers that do not provide ordinary user accounts, your user-id and
497 password are usually assigned by the server administrator when you apply for
498 a mailbox on the server. Contact your server administrator if you don't know
499 the correct user-id and password for your mailbox account.
501 Early versions of POP3 (RFC1081, RFC1225) supported a crude form of
502 independent authentication using the
504 file on the mailserver side. Under this RPOP variant, a fixed
505 per-user ID equivalent to a password was sent in clear over a link to
506 a reserved port, with the command RPOP rather than PASS to alert the
507 server that it should do special checking. RPOP is supported
510 (you can specify `protocol RPOP' to have the program send `RPOP'
511 rather than `PASS') but its use is strongly discouraged. This
512 facility was vulnerable to spoofing and was withdrawn in RFC1460.
514 RFC1460 introduced APOP authentication. In this variant of POP3,
515 you register an APOP password on your server host (the program
516 to do this with on the server is probably called \fIpopauth\fR(8)). You
517 put the same password in your
521 logs in, it sends a cryptographically secure hash of your password and
522 the server greeting time to the server, which can verify it by
523 checking its authorization database.
525 If your \fIfetchmail\fR was built with Kerberos support and you specify
526 Kerberos preauthentication (either with --auth or the \fI.fetchmailrc\fR
527 option \fBauthenticate kerberos_v4\fR) it will try to get a Kerberos
528 ticket from the mailserver at the start of each query.
530 If you use IMAP-K4, \fIfetchmail\fR will expect the IMAP server to have
531 RFC1731-conformant AUTHENTICATE KERBEROS_V4 capability, and will use it.
533 If you use IMAP-GSS, \fIfetchmail\fR will expect the IMAP server to have
534 RFC1731-conformant AUTHENTICATE GSSAPI capability, and will use it.
535 Currently this has only been tested over Kerberos V, so you're expected
536 to already have a ticket-granting ticket. You may pass a username different
537 from your principal name using the standard \fB--user\fR command or by
538 the \fI.fetchmailrc\fR option \fBuser\fR.
540 If you are using POP3, and the server issues a one-time-password
541 challenge conforming to RFC1938, \fIfetchmail\fR will use your
542 password as a pass phrase to generate the required response. This
543 avoids sending secrets over the net unencrypted.
545 Compuserve's RPA authentication (similar to APOP) is supported. If
546 you are using POP3, and the RPA code has been compiled into your
547 binary, and you query a server in the Compuserve csi.com domain,
548 \fIfetchmail\fR will try to perform an RPA pass-phrase authentication
549 instead of sending over the password en clair.
551 If you are using IPsec, the -T (--netsec) option can be used to pass
552 an IP security request to be used when outgoing IP connections are
553 initialized. You can also do this using the `netsec' server option
554 in the .fetchmailrc file. In either case, the option value is a
555 string in the format accepted by the net_security_strtorequest()
556 function of the inet6_apps library.
565 in daemon mode. You must specify a numeric argument which is a
566 polling interval in seconds.
570 puts itself in background and runs forever, querying each specified
571 host and then sleeping for the given polling interval.
577 will, therefore, poll all the hosts described in your
579 file (except those explicitly excluded with the `skip' verb) once
580 every fifteen minutes.
582 It is possible to set a polling interval
585 file by saying `set daemon <interval>', where <interval> is an
586 integer number of seconds. If you do this, fetchmail will always
587 start in daemon mode unless you override it with the command-line
588 option --daemon 0 or -d0.
590 Only one daemon process is permitted per user; in daemon mode,
592 makes a per-user lockfile to guarantee this.
594 Normally, calling fetchmail with a daemon in the background sends a
595 wakeup signal to the daemon, forcing it to poll mailservers
596 immediately. (The wakeup signal is SIGHUP if fetchmail is running as
597 root, SIGUSR1 otherwise.)
601 will kill a running daemon process instead of waking it up (if there
604 notifies you). If the --quit option is the only command-line option,
605 that's all there is to it.
607 The quit option may also be mixed with other command-line options; its
608 effect is to kill any running daemon before doing what the other
609 options specify in combination with the rc file.
615 option (keyword: timeout) allows you to set a server-nonresponse
616 timeout in seconds. If a mailserver does not send a greeting message
617 or respond to commands for the given number of seconds,
618 \fIfetchmail\fR will hang up on it. Without such a timeout
619 \fIfetchmail\fR might hang up indefinitely trying to fetch mail from a
620 down host. This would be particularly annoying for a \fIfetchmail\fR
621 running in background. There is a default timeout which fetchmail -V
628 option (keyword: set logfile) allows you to redirect status messages
629 emitted while detached into a specified logfile (follow the
630 option with the logfile name). The logfile is opened for append, so
631 previous messages aren't deleted. This is primarily useful for
632 debugging configurations.
636 option (keyword: set syslog) allows you to redirect status and error
637 messages emitted to the
639 system daemon if available.
640 Messages are logged with an id of \fBfetchmail\fR, the facility \fBLOG_MAIL\fR,
641 and priorities \fBLOG_ERR\fR, \fBLOG_ALERT\fR or \fBLOG_INFO\fR.
642 This option is intended for logging status and error messages which
643 indicate the status of the daemon and the results while fetching mail
645 Error messages for command line options and parsing the \fI.fetchmailrc\fR
646 file are still written to stderr, or the specified log file if the
649 option turns off use of
651 assuming it's turned on in the
661 or --nodetach option suppresses backgrounding and detachment of the
662 daemon process from its control terminal. This is primarily useful
663 for debugging. Note that this also causes the logfile option to be
664 ignored (though perhaps it shouldn't).
666 Note that while running in daemon mode polling a POP2 or IMAP2bis server,
667 transient errors (such as DNS failures or sendmail delivery refusals)
668 may force the fetchall option on for the duration of the next polling
669 cycle. This is a robustness feature. It means that if a message is
670 fetched (and thus marked seen by the mailserver) but not delivered
671 locally due to some transient error, it will be re-fetched during the
672 next poll cycle. (The IMAP logic doesn't delete messages until
673 they're delivered, so this problem does not arise.)
675 .SH ADMINISTRATIVE OPTIONS
679 option (keyword: set postmaster) specifies the last-resort username to
680 which multidrop mail is to be forwarded if no matching local recipient
681 can be found. Normally this is just the user who invoked fetchmail.
682 If the invoking user is root, then the default of this option is
683 the user `postmaster'.
687 option (keyword: set invisible) tries to make fetchmail invisible.
688 Normally, fetchmail behaves like any other MTA would -- it generates a
689 Received header into each message describing its place in the chain of
690 transmission, and tells the MTA it forwards to that the mail came from
691 the machine fetchmail itself is running on. If the invisible option
692 is on, the Received header is suppressed and fetchmail tries to spoof
693 the MTA it forwards to into thinking it came directly from the
696 .SH RETRIEVAL FAILURE MODES
697 The protocols \fIfetchmail\fR uses to talk to mailservers are next to
698 bulletproof. In normal operation forwarding to port 25, no message is
699 ever deleted (or even marked for deletion) on the host until the SMTP
700 listener on the client has acknowledged to \fIfetchmail\fR that the
701 message has been accepted for delivery. When forwarding to an MDA,
702 however, there is more possibility of error (because there's no way
703 for fetchmail to get a reliable positive acknowledgement from the MDA).
705 The normal mode of \fIfetchmail\fR is to try to download only `new'
706 messages, leaving untouched (and undeleted) messages you have already
707 read directly on the server (or fetched with a previous \fIfetchmail
708 --keep\fR). But you may find that messages you've already read on the
709 server are being fetched (and deleted) even when you don't specify
710 --all. There are several reasons this can happen.
712 One could be that you're using POP2. The POP2 protocol includes no
713 representation of `new' or `old' state in messages, so \fIfetchmail\fR
714 must treat all messages as new all the time. But POP2 is obsolete, so
717 Under POP3, blame RFC1725. That version of the POP3 protocol
718 specification removed the LAST command, and some POP servers follow it
719 (you can verify this by invoking \fIfetchmail -v\fR to the mailserver
720 and watching the response to LAST early in the query). The
721 \fIfetchmail\fR code tries to compensate by using POP3's UID feature,
722 storing the identifiers of messages seen in each session until the
723 next session, in the \fI.fetchids\fR file. But this doesn't track
724 messages seen with other clients, or read directly with a mailer on
725 the host but not deleted afterward. A better solution would be to
728 Another potential POP3 problem might be servers that insert messages
729 in the middle of mailboxes (some VMS implementations of mail are
730 rumored to do this). The \fIfetchmail\fR code assumes that new
731 messages are appended to the end of the mailbox; when this is not true
732 it may treat some old messages as new and vice versa. The only
733 real fix for this problem is to switch to IMAP.
735 The IMAP code uses the presence or absence of the server flag \eSeen
736 to decide whether or not a message is new. Under Unix, it counts on
737 your IMAP server to notice the BSD-style Status flags set by mail user
738 agents and set the \eSeen flag from them when appropriate. All Unix
739 IMAP servers we know of do this, though it's not specified by the IMAP
740 RFCs. If you ever trip over a server that doesn't, the symptom will
741 be that messages you have already read on your host will look new to
742 the server. In this (unlikely) case, only messages you fetched with
743 \fIfetchmail --keep\fR will be both undeleted and marked old.
745 In ETRN mode, \fIfetchmail\fR does not actually retrieve messages;
746 instead, it asks the server's SMTP listener to start a queue flush
747 to the client via SMTP. Therefore it sends only undelivered messages.
750 Many SMTP listeners allow administrators to set up `spam filters' that
751 block unsolicited email from specified domains. A MAIL FROM line that
752 triggers this feature will elicit an SMTP response which
753 (unfortunately) varies according to the listener.
757 return an error code of 571. This return value
758 is blessed by RFC1893 as "Delivery not authorized, message refused".
760 According to current drafts of the replacement for RFC821, the correct
761 thing to return in this situation is 550 "Requested action not taken:
762 mailbox unavailable" (the draft adds "[E.g., mailbox not found, no
763 access, or command rejected for policy reasons].").
767 MTA returns 501 "Syntax error in parameters or arguments" , but will
772 code recognizes and discards the message on a code that defaults to
773 sendmail's 571 but can be set with the `antispam' option. This is the
775 circumstance under which fetchmail ever discards mail.
779 is fetching from an IMAP server, the antispam response will be detected and
780 the message rejected immediately after the headers have been fetched,
781 without reading the message body. Thus, you won't pay for downloading
784 .SH THE RUN CONTROL FILE
785 The preferred way to set up fetchmail is to write a
786 \&\fI.fetchmailrc\fR file in your home directory. When there is a
787 conflict between the command-line arguments and the arguments in this
788 file, the command-line arguments take precedence.
790 To protect the security of your passwords, when --version is not on
791 your \fI~/.fetchmailrc\fR may not have more than 0600 (u=rw,g=,o=) permissions;
793 will complain and exit otherwise.
795 You may read the \fI.fetchmailrc\fR file as a list of commands to
798 is called with no arguments.
799 .SS Run Control Syntax
801 Comments begin with a '#' and extend through the end of the line.
802 Otherwise the file consists of a series of server entries or global
803 option statements in a free-format, token-oriented syntax.
805 There are four kinds of tokens: grammar keywords, numbers
806 (i.e. decimal digit sequences), unquoted strings, and quoted strings.
807 A quoted string is bounded by double quotes and may contain
808 whitespace (and quoted digits are treated as a string). An unquoted
809 string is any whitespace-delimited token that is neither numeric, string
810 quoted nor contains the special characters `,', `;', `:', or `='.
812 Any amount of whitespace separates tokens in server entries, but is
813 otherwise ignored. You may use standard C-style escapes (\en, \et,
814 \eb, octal, and hex) to embed non-printable characters or string
815 delimiters in strings.
817 Each server entry consists of one of the keywords `poll' or `skip',
818 followed by a server name, followed by server options, followed by any
819 number of user descriptions. Note: the most common cause of syntax
820 errors is mixing up user and server options.
822 For backward compatibility, the word `server' is a synonym for `poll'.
824 You can use the noise keywords `and', `with',
825 \&`has', `wants', and `options' anywhere in an entry to make
826 it resemble English. They're ignored, but but can make entries much
827 easier to read at a glance. The punctuation characters ':', ';' and
828 \&',' are also ignored.
831 The `poll' verb tells fetchmail to query this host when it is run with
832 no arguments. The `skip' verb tells
834 not to poll this host unless it is explicitly named on the command
835 line. (The `skip' verb allows you to experiment with test entries
836 safely, or easily disable entries for hosts that are temporarily down.)
838 .SS Keyword/Option Summary
839 Here are the legal server options. Keyword suffixes enclosed in
840 square brackets are optional. Those corresponding to command-line
841 options are followed by `-' and the appropriate option letter.
848 Specify DNS name of mailserver, overriding poll name
851 Specify protocol (case insensitive):
852 POP2, POP3, IMAP, IMAP-K4, IMAP-GSS, APOP, KPOP
855 Specify TCP/IP service port
858 Set preauthentication type (default `password')
861 Server inactivity timout in seconds (default 300)
864 Specify envelope-address header name
867 Disable looking for envelope address
870 Qmail virtual domain prefix to remove from user name
873 Specify alternate DNS names of mailserver
876 specify IP interface(s) that must be up for server poll to take place
879 Specify IP address to monitor for activity
882 Enable DNS lookup for multidrop (default)
885 Disable DNS lookup for multidrop
888 Do comparison by IP address for multidrop
891 Do comparison by name for multidrop (default)
894 Force POP3 to use client-side UIDLs
897 Turn off POP3 use of client-side UIDLs (default)
901 Here are the legal user options:
909 (local user name if name followed by `here')
912 Connect local and remote user names
915 Connect local and remote user names
918 Specify remote account password
921 Specify remote folder to query
924 Specify smtp host(s) to forward to
927 Specify the domain to be put in RCPT TO lines
930 Specify what SMTP return is interpreted as a spam-policy block
933 Specify MDA for local delivery
936 Command to be executed before each connection
939 Command to be executed after each connection
942 Don't delete seen messages from server
945 Flush all seen messages before querying
948 Fetch all messages whether seen or not
951 Rewrite destination addresses for reply (default)
954 Strip carriage returns from ends of lines
957 Force carriage returns at ends of lines
960 Force BODY=8BITMIME to ESMTP listener
963 Strip Status and X-Mozilla-Status lines out of incoming mail
966 Convert quoted-printable to 8-bit in MIME messages
969 Delete seen messages from server (default)
972 Don't flush all seen messages before querying (default)
975 Retrieve only new messages (default)
978 Don't rewrite headers
981 Don't strip carriage returns (default)
984 Don't force carriage returns at EOL (default)
987 Don't force BODY=8BITMIME to ESMTP listener (default)
990 Don't drop Status headers (default)
993 Don't convert quoted-printable to 8-bit in MIME messages (default)
996 Set message size limit
999 Max # messages to fetch in single connect
1002 Max # messages to forward in single connect
1005 Perform an expunge on every #th message (IMAP only)
1008 Do error logging through syslog(3).
1011 Turn off error logging through syslog(3).
1015 Remember that all user options must \fIfollow\fR all server options.
1017 In the .fetchmailrc file, the `envelope' string argument may be
1018 preceded by a whitespace-separated number. This number, if specified,
1019 is the number of such headers to skip (that is, an argument of 1
1020 selects the second header of the given type). This is sometime useful
1021 for ignoring bogus Received headers created by an ISP's local delivery
1023 .SS Keywords Not Corresponding To Option Switches
1025 The `folder' and `smtphost' options (unlike their command-line
1026 equivalents) can take a space- or comma-separated list of names
1029 All options correspond to the obvious command-line arguments, except
1030 the following: `via', `interval', `aka', `is', `to', `dns'/`no dns',
1031 `checkalias'/`no checkalias',
1032 \&`password', \&`preconnect', \&`postconnect', `localdomains',
1033 \&`stripcr'/`no stripcr', \&`forcecr'/`no forcecr', `pass8bits'/`no
1034 pass8bits' `dropstatus/no dropstatus', `mimedecode/no mimedecode',
1037 The `via' option is for use with ssh, or if you want to have more
1038 than one configuration pointing at the same site. If it is present,
1039 the string argument will be taken as the actual DNS name of the
1040 mailserver host to query.
1041 This will override the argument of poll, which can then simply be a
1042 distinct label for the configuration (e.g. what you would give on the
1043 command line to explicitly query this host).
1044 If the `via' name is `localhost', the poll name will also still be
1045 used as a possible match in multidrop mode; otherwise the `via' name
1046 will be used instead and the poll name will be purely a label.
1048 The `interval' option (which takes a numeric argument) allows you to poll a
1049 server less frequently than the basic poll interval. If you say
1050 \&`interval N' the server this option is attached to will only be
1051 queried every N poll intervals.
1053 The `is' or `to' keywords associate the following local (client)
1054 name(s) (or server-name to client-name mappings separated by =) with
1055 the mailserver user name in the entry. If an is/to list has `*' as
1056 its last name, unrecognized names are simply passed through.
1058 A single local name can be used to support redirecting your mail when
1059 your username on the client machine is different from your name on the
1060 mailserver. When there is only a single local name, mail is forwarded
1061 to that local username regardless of the message's Received, To, Cc,
1062 and Bcc headers. In this case
1064 never does DNS lookups.
1066 When there is more than one local name (or name mapping) the
1067 \fIfetchmail\fR code does look at the Received, To, Cc, and Bcc
1068 headers of retrieved mail (this is `multidrop mode'). It looks for
1069 addresses with hostname parts that match your poll name or your `via',
1070 `aka' or `localdomains' options, and usually also for hostname parts
1071 which DNS tells it are aliases of the mailserver. See the discussion
1072 of `dns', `checkalias', `localdomains', and `aka' for details on how
1073 matching addresses are handled.
1075 If \fIfetchmail\fR cannot match any mailserver usernames or
1076 localdomain addresses, the default recipient is the value of the
1077 `postmaster' global option if that has been set; otherwise it's the
1078 calling user (as set by the USER or LOGNAME variable in the
1081 The `dns' option (normally on) controls the way addresses from
1082 multidrop mailboxes are checked. On, it enables logic to check each
1083 host address that doesn't match an `aka' or `localdomains' declaration
1084 by looking it up with DNS. When a mailserver username is recognized
1085 attached to a matching hostname part, its local mapping is added to
1086 the list of local recipients.
1088 The `checkalias' option (normally off) extends the lookups performed
1089 by the `dns' keyword in multidrop mode, providing a way to cope with
1090 remote MTAs that identify themselves using their canonical name, while
1091 they're polled using an alias.
1092 When such a server is polled, checks to extract the envelope address
1095 reverts to delivery using the To/Cc/Bcc headers (See below
1096 `Header vs. Envelope addresses').
1097 Specifying this option instructs
1099 to retrieve all the IP addresses associated with both the poll name
1100 and the name used by the remote MTA and to do a comparison of the IP
1101 addresses. This comes in handy in situations where the remote server
1102 undergoes frequent canonical name changes, that would otherwise
1103 require modifications to the rcfile. `checkalias' has no effect if
1104 `no dns' is specified in the rcfile.
1106 The `aka' option is for use with multidrop mailboxes. It allows you
1107 to pre-declare a list of DNS aliases for a server. This is an
1108 optimization hack that allows you to trade space for speed. When
1110 while processing a multidrop mailbox, grovels through message headers
1111 looking for names of the mailserver, pre-declaring common ones can
1112 save it from having to do DNS lookups.
1114 The `localdomains' option allows you to declare a list of domains
1115 which fetchmail should consider local. When fetchmail is parsing
1116 address lines in multidrop modes, and a trailing segment of a host
1117 name matches a declared local domain, that address is passed through
1118 to the listener or MDA unaltered (local-name mappings are \fInot\fR
1121 If you are using `localdomains', you may also need to specify \&`no
1122 envelope', which disables \fIfetchmail\fR's normal attempt to deduce
1123 an envelope address from the Received line or X-Envelope-To header or
1124 whatever header has been previously set by `envelope'. If you set `no
1125 envelope' in the defaults entry it is possible to undo that in
1126 individual entries by using `envelope <string>'. As a special case,
1127 \&`envelope "Received"' restores the default parsing of
1130 The \fBpassword\fR option requires a string argument, which is the password
1131 to be used with the entry's server.
1133 The `preconnect' keyword allows you to specify a shell command to be
1134 executed just before each time
1136 establishes a mailserver connection. This may be useful if you are
1137 attempting to set up secure POP connections with the aid of
1139 If the command returns a nonzero status, the poll of that mailserver
1142 Similarly, the `postconnect' keyword similarly allows you to specify a
1143 shell command to be executed just after each time a mailserver
1144 connection is taken down.
1146 The `forcecr' option controls whether lines terminated by LF only are
1147 given CRLF termination before forwarding. Strictly speaking RFC821
1148 requires this, but few MTAs enforce the requirement it so this option
1149 is normally off (only one such MTA, qmail, is in significant use at
1152 The `stripcr' option controls whether carriage returns are stripped
1153 out of retrieved mail before it is forwarded. It is normally not
1154 necessary to set this, because it defaults to `on' (CR stripping
1155 enabled) when there is an MDA declared but `off' (CR stripping
1156 disabled) when forwarding is via SMTP. If `stripcr' and `forcecr' are
1157 both on, `stripcr' will override.
1159 The `pass8bits' option exists to cope with Microsoft mail programs that
1160 stupidly slap a "Content-Transfer-Encoding: 7bit" on everything. With
1161 this option off (the default) and such a header present,
1163 declares BODY=7BIT to an ESMTP-capable listener; this causes problems for
1164 messages actually using 8-bit ISO or KOI-8 character sets, which will
1165 be garbled by having the high bits of all characters stripped. If
1166 \&`pass8bits' is on,
1168 is forced to declare BODY=8BITMIME to any ESMTP-capable listener. If
1169 the listener is 8-bit-clean (as all the major ones now are) the right
1170 thing will probably result.
1172 The `dropstatus' option controls whether nonempty Status and
1173 X-Mozilla-Status lines are retained in fetched mail (the default) or
1174 discarded. Retaining them allows your MUA to see what messages (if
1175 any) were marked seen on the server. On the other hand, it can
1176 confuse some new-mail notifiers, which assume that anything with a
1177 Status line in it has been seen. (Note: the empty Status lines
1178 inserted by some buggy POP servers are unconditionally discarded.)
1180 The `mimedecode' option controls whether MIME messages using the
1181 quoted-printable encoding are automatically converted into pure
1182 8-bit data. If you are delivering mail to an ESMTP-capable,
1183 8-bit-clean listener (that includes all of the major programs
1184 like sendmail), then this will automatically convert quoted-printable
1185 message headers and data into 8-bit data, making it easier to
1186 understand when reading mail. If your e-mail programs know how to
1187 deal with MIME messages, then this option is not needed.
1189 .SS Miscellaneous Run Control Options
1190 The words `here' and `there' have useful English-like
1191 significance. Normally `user eric is esr' would mean that
1192 mail for the remote user `eric' is to be delivered to `esr',
1193 but you can make this clearer by saying `user eric there is esr here',
1194 or reverse it by saying `user esr here is eric there'
1196 Legal protocol identifiers for use with the `protocol' keyword are:
1202 imap-k4 (or IMAP-K4)
1203 imap-gss (or IMAP-GSS)
1208 Legal authentication types are `password' or `kerberos'. The former
1209 specifies authentication by normal transmission of a password (the
1210 password may be plaintext or subject to protocol-specific encryption
1211 as in APOP); the second tells \fIfetchmail\fR to try to get a Kerberos
1212 ticket at the start of each query instead, and send an arbitrary
1213 string as the password.
1215 Specifying `kpop' sets POP3 protocol over port 1109 with Kerberos V4
1216 preauthentication. These defaults may be overridden by later options.
1218 There are currently three global option statements; `set logfile'
1219 followed by a string sets the same global specified by --logfile. A
1220 command-line --logfile option will override this. Also, `set daemon'
1221 sets the poll interval as --daemon does. This can be overridden by
1222 a command-line --daemon option; in particular --daemon 0 can be used
1223 to force foreground operation. Finally, `set syslog' sends log
1224 messages to syslogd(8).
1226 .SH INTERACTION WITH RFC 822
1227 When trying to detertmine the originating address of a message,
1228 fetchmail looks through headers in the following order:
1238 The originating address is used for logging, and to set the MAIL FROM
1239 address when forwarding to SMTP. This order is intended to cope
1240 gracefully with receiving mailing list messages in multidrop mode. The
1241 intent is that if a local address doesn't exist, the bounce message
1242 won't be returned blindly to the author or to the list itself, but
1243 rather to the list manager (which is less annoying).
1245 In multidrop mode, destination headers are processed as follows:
1246 First, fetchmail looks for the Received: header (or whichever one is
1247 specified by the `envelope' option) to determine the local
1248 recipient adress. If the mail is addressed to more than one recipient,
1249 the Received line won't contain any information regarding recipient adresses.
1251 Then fetchmail looks for the Resent-To:, Resent-Cc:, and Resent-Bcc:
1252 lines. If they exists, they should contain the final recipients and
1253 have precedence over their To:/Cc:/Bcc: counterparts. If the Resent-*
1254 lines doesn't exist, the To:, Cc:, Bcc: and Apparently-To: lines are
1255 looked for. (The presence of a Resent-To: is taken to impluy that the
1256 person referred by the To: address has already received the original
1259 .SH CONFIGURATION EXAMPLES
1263 poll SERVERNAME protocol PROTOCOL username NAME password PASSWORD
1269 poll pop.provider.net protocol pop3 username jsmith password secret1
1272 Or, using some abbreviations:
1275 poll pop.provider.net proto pop3 user jsmith password secret1
1278 Multiple servers may be listed:
1281 poll pop.provider.net proto pop3 user jsmith pass secret1
1282 poll other.provider.net proto pop2 user John.Smith pass My^Hat
1285 Here's a version of those two with more whitespace and some noise words:
1288 poll pop.provider.net proto pop3
1289 user jsmith, with password secret1, is jsmith here;
1290 poll other.provider.net proto pop2:
1291 user John.Smith, with password My^Hat, is John.Smith here;
1294 This version is much easier to read and doesn't cost significantly
1295 more (parsing is done only once, at startup time).
1298 If you need to include whitespace in a parameter string, enclose the
1299 string in double quotes. Thus:
1302 poll mail.provider.net with proto pop3:
1303 user jsmith there has password "u can't krak this"
1304 is jws here and wants mda "/bin/mail"
1307 You may have an initial server description headed by the keyword
1308 `defaults' instead of `poll' followed by a name. Such a record
1309 is interpreted as defaults for all queries to use. It may be overwritten
1310 by individual server descriptions. So, you could write:
1315 poll pop.provider.net
1317 poll mail.provider.net
1318 user jjsmith there has password secret2
1321 It's possible to specify more than one user per server (this is only
1322 likely to be useful when running fetchmail in daemon mode as root).
1323 The `user' keyword leads off a user description, and every user specification
1324 in a multi-user entry must include it. Here's an example:
1327 poll pop.provider.net proto pop3 port 3111
1328 user jsmith with pass secret1 is smith here
1329 user jones with pass secret2 is jjones here
1332 This associates the local username `smith' with the pop.provider.net
1333 username `jsmith' and the local username `jjones' with the
1334 pop.provider.net username `jones'.
1336 Here's what a simple retrieval configuration for a multi-drop mailbox
1340 poll pop.provider.net:
1341 user maildrop with pass secret1 to golux hurkle=happy snark here
1344 This says that the mailbox of account `maildrop' on the server is a
1345 multi-drop box, and that messages in it should be parsed for the
1346 server user names `golux', `hurkle', and `snark'. It further
1347 specifies that `golux' and `snark' have the same name on the
1348 client as on the server, but mail for server user `hurkle' should be
1349 delivered to client user `happy'.
1351 Here's an example of another kind of multidrop connection:
1354 poll pop.provider.net localdomains loonytoons.org:
1355 user maildrop with pass secret1 to esr * here
1358 This also says that the mailbox of account `maildrop' on the server is
1359 a multi-drop box. It tells fetchmail that any address in the
1360 loonytoons.org domain (including subdomain addresses like
1361 `joe@daffy.loonytoons.org') should be passed through to the local SMTP
1362 listener without modification. Be careful of mail loops if you do this!
1364 Here's an example configuration using ssh. The queries go through an
1365 ssh connecting local port 1234 to port 110 on mailhost.net; the
1366 preconnect command sets up the ssh.
1369 poll mailhost.net via localhost port 1234 with proto pop3:
1370 preconnect "ssh -f -L 1234:mailhost.net:110
1371 mailhost.net sleep 20 </dev/null >/dev/null";
1374 .SH THE USE AND ABUSE OF MULTIDROP MAILBOXES
1375 Use the multiple-local-recipients feature with caution -- it can bite.
1376 Also note that all multidrop features are ineffective in ETRN mode.
1378 .SS Header vs. Envelope addresses
1379 The fundamental problem is that by having your mailserver toss several
1380 peoples' mail in a single maildrop box, you may have thrown away
1381 potentially vital information about who each piece of mail was
1382 actually addressed to (the `envelope address', as opposed to the
1383 header addresses in the RFC822 To/Cc/Bcc headers). This `envelope
1384 address' is the address you need in order to reroute mail properly.
1388 can deduce the envelope address. If the mailserver MTA is
1390 and the item of mail had just one recipient, the MTA will have written
1391 a `by/for' clause that gives the envelope addressee into its Received
1392 header. But this doesn't work reliably for other MTAs, nor if there is
1393 more than one recipient. By default, \fIfetchmail\fR looks for
1394 envelope addresses in these lines; you can restore this default with
1395 -E "Received" or \&`envelope Received'.
1397 Alternatively, some SMTP listeners and/or mail servers insert a header
1398 in each message containing a copy of the envelope addresses. This
1399 header (when it exists) is often `X-Envelope-To'. Fetchmail's
1400 assumption about this can be changed with the -E or `envelope' option.
1401 Note that writing an envelope header of this kind exposes the names of
1402 recipients (including blind-copy recopients) to all receivers of the
1403 messages; it is therefore regarded by some administrators as a
1404 security/privacy problem.
1406 A slight variation of the `X-Envelope-To' header is the `Delivered-To' put
1407 by qmail to avoid mail loops. It will probably prefix the user name with a
1408 string that normally matches the user's domain. To remove this prefix you
1409 can use the -Q or `qvirtual' option.
1411 Sometimes, unfortunately, neither of these methods works. When they
1412 all fail, fetchmail must fall back on the contents of To/Cc/Bcc
1413 headers to try to determine recipient addressees -- and these are not
1414 reliable. In particular, mailing-list software often ships mail with
1415 only the list broadcast address in the To header.
1419 cannot deduce a recipient address that is local, and the intended
1420 recipient address was anyone other than fetchmail's invoking user,
1421 mail will get lost. This is what makes the multidrop feature risky.
1423 A related problem is that when you blind-copy a mail message, the Bcc
1424 information is carried \fIonly\fR as envelope address (it's not put
1425 in the headers fetchmail can see unless there is an X-Envelope
1426 header). Thus, blind-copying to someone who gets mail over a
1427 fetchmail link will fail unless the the mailserver host routinely
1428 writes X-Envelope or an equivalent header into messages in your maildrop.
1430 .SS Good Ways To Use Multidrop Mailboxes
1431 Multiple local names can be used to administer a mailing list from the
1432 client side of a \fIfetchmail\fR collection. Suppose your name is
1433 \&`esr', and you want to both pick up your own mail and maintain a mailing
1434 list called (say) "fetchmail-friends", and you want to keep the alias
1435 list on your client machine.
1437 On your server, you can alias \&`fetchmail-friends' to `esr'; then, in
1438 your \fI.fetchmailrc\fR, declare \&`to esr fetchmail-friends here'.
1439 Then, when mail including `fetchmail-friends' as a local address
1440 gets fetched, the list name will be appended to the list of
1441 recipients your SMTP listener sees. Therefore it will undergo alias
1442 expansion locally. Be sure to include `esr' in the local alias
1443 expansion of fetchmail-friends, or you'll never see mail sent only to
1444 the list. Also be sure that your listener has the "me-too" option set
1445 (sendmail's -oXm command-line option or OXm declaration) so your name
1446 isn't removed from alias expansions in messages you send.
1448 This trick is not without its problems, however. You'll begin to see
1449 this when a message comes in that is addressed only to a mailing list
1450 you do \fInot\fR have declared as a local name. Each such message
1451 will feature an `X-Fetchmail-Warning' header which is generated
1452 because fetchmail cannot find a valid local name in the recipient
1453 addresses. Such messages default (as was described above) to being
1454 sent to the local user running
1456 but the program has no way to know that that's actually the right thing.
1458 .SS Bad Ways To Abuse Multidrop Mailboxes
1459 Multidrop mailboxes and
1461 serving multiple users in daemon mode do not mix. The problem, again, is
1462 mail from mailing lists, which typically does not have an individual
1463 recipient address on it. Unless
1465 can deduce an envelope address, such mail will only go to the account
1466 running fetchmail (probably root). Also, blind-copied users are very
1467 likely never to see their mail at all.
1469 If you're tempted to use
1471 to retrieve mail for multiple users from a single mail drop via POP or
1472 IMAP, think again (and reread the section on header and envelope
1473 addresses above). It would be smarter to just let the mail sit in the
1474 mailserver's queue and use fetchmail's ETRN mode to trigger SMTP sends
1475 periodically (of course, this means you have to poll more frequently
1476 than the mailserver's expiry period). If you can't arrange this, try
1477 setting up a UUCP feed.
1479 If you absolutely \fImust\fR use multidrop for this purpose, make sure
1480 your mailserver writes an envelope-address header that fetchmail can
1481 see. Otherwise you \fIwill\fR lose mail and it \fIwill\fR come back
1484 .SS Speeding Up Multidrop Checking
1485 Normally, when multiple user are declared
1487 extracts recipient addresses as described above and checks each host
1488 part with DNS to see if it's an alias of the mailserver. If so, the
1489 name mappings described in the to ... here declaration are done and
1490 the mail locally delivered.
1492 This is the safest but also slowest method. To speed it up,
1493 pre-declare mailserver aliases with `aka'; these are checked before
1494 DNS lookups are done. If you're certain your aka list contains
1496 DNS aliases of the mailserver (and all MX names pointing at it)
1497 you can declare `no dns' to suppress DNS lookups entirely and
1498 \fIonly\fR match against the aka list.
1501 To facilitate the use of
1503 in shell scripts, an exit code is returned to give an indication
1504 of what occurred during a given connection.
1506 The exit codes returned by
1510 One or more messages were successfully retrieved.
1512 There was no mail awaiting retrieval. (There may have been old mail still
1513 on the server but not selected for retrieval.)
1515 An error was encountered when attempting to open a socket for the POP
1516 connection. If you don't know what a socket is, don't worry about it --
1517 just treat this as an 'unrecoverable error'.
1519 The user authentication step failed. This usually means that a bad
1520 user-id, password, or APOP id was specified.
1522 Some sort of fatal protocol error was detected.
1524 There was a syntax error in the arguments to
1527 The run control file had bad permissions.
1529 There was an error condition reported by the server. Can also
1532 timed out while waiting for the server.
1534 Client-side exclusion error. This means
1536 either found another copy of itself already running, or failed in such
1537 a way that it isn't sure whether another copy is running.
1539 The user authentication step failed because the server responded "lock
1540 busy". Try again after a brief pause! This error is not implemented
1541 for all protocols, nor for all servers. If not implemented for your
1542 server, "3" will be returned instead, see above. May be returned when
1543 talking to qpopper or other servers that can respond with "lock busy"
1544 or some similar text containing the word "lock".
1548 run failed while trying to do an SMTP port open or transaction.
1550 Fatal DNS error. Fetchmail encountered an error while performing
1551 a DNS lookup at startup and could not proceed.
1553 Internal error. You should see a message on standard error with
1558 queries more than one host, return status is 0 if \fIany\fR query
1559 successfully retrieved mail. Otherwise the returned error status is
1560 that of the last host queried.
1563 Eric S. Raymond <esr@snark.thyrsus.com>.
1564 This program is descended from and replaces
1566 by Carl Harris <ceharris@mal.com>; the internals are quite different,
1567 but some of its interface design is directly traceable to that
1573 default run control file
1576 default location of file associating hosts with last message IDs seen
1577 (used only with newer RFC1725-compliant POP3 servers supporting the
1581 your FTP run control file, which (if present) will be searched for
1582 passwords as a last resort before prompting for one interactively.
1585 lock file to help prevent concurrent runs (non-root mode).
1587 /var/run/fetchmail.pid
1588 lock file to help prevent concurrent runs (root mode, Linux systems).
1591 lock file to help prevent concurrent runs (root mode, systems without /var/run).
1594 For correct initialization,
1596 requires either that both the USER and HOME environment variables are
1597 correctly set, or that \fBgetpwuid\fR(3) be able to retrieve a password
1598 entry from your user ID.
1603 daemon is running as root, SIGHUP wakes it up from its sleep phase and
1604 forces a poll of all non-skipped servers (this is in accordance with
1605 the usual conventions for system daemons).
1609 is running in daemon mode as non-root, use SIGUSR1 to wake it (this is
1610 so SIGHUP due to logout can retain the default action of killing it).
1614 in foreground while a background fetchmail is running will do
1615 whichever of these is appropriate to wake it up.
1617 .SH BUGS AND KNOWN PROBLEMS
1618 Enabling the `mimedecode' option (which defaults to off) may render
1619 invalid any PGP signatures attached to mail with quoted-printable headers.
1620 This bug will be fixed in a future version.
1622 The RFC822 address parser used in multidrop mode chokes on some
1623 @-addresses that are technically legal but bizarre. Strange uses of
1624 quoting and embedded comments are likely to confuse it.
1626 Use of any of the supported protocols other than POP3 with OTP or RPA, APOP,
1627 KPOP, IMAP-K4, IMAP-GSS, or ETRN requires that the program send unencrypted
1628 passwords over the TCP/IP connection to the mailserver. This creates
1629 a risk that name/password pairs might be snaffled with a packet
1630 sniffer or more sophisticated monitoring software. Under Linux, the
1631 --interface option can be used to restrict polling to availability of
1632 a specific interface device with a specific local IP address, but
1633 snooping is still possible if (a) either host has a network device
1634 that can be opened in promiscuous mode, or (b) the intervening network
1637 Use of the %F or %T escapes in an mda option could open a security
1638 hole, because they pass text manipulable by an attacker to a shell
1639 command. Potential shell characters are replaced by `_' before
1640 execution. The hole is further reduced by the fact that fetchmail
1641 temporarily discards any suid privileges it may have while running the
1642 MDA. For maximum safety, however, don't use an mda command containing
1643 %F or %T when fetchmail is run from the root account itself.
1645 Send comments, bug reports, gripes, and the like to Eric S. Raymond
1646 <esr@thyrsus.com>. An HTML FAQ is available at the fetchmail home
1647 page; surf to http://www.tuxedo.org/~esr/fetchmail or do a WWW search
1648 for pages with `fetchmail' in their titles.
1651 elm(1), mail(1), sendmail(8), popd(8), imapd(8)
1652 .SH APPLICABLE STANDARDS
1655 RFC 821, RFC 1869, RFC 1652, RFC 1870, RFC1983, RFC 1985
1664 RFC 1081, RFC 1225, RFC 1460, RFC 1725, RFC 1939
1667 RFC 1460, RFC 1725, RFC 1939
1676 RFC 1730, RFC 1731, RFC 1732, RFC 2060, RFC 2061
projects / ~andy / fetchmail / blob