.\" Copyright 1993-95 by Carl Harris, Jr. Copyright 1996 by Eric S. Raymond
.\" All rights reserved.
.\" For license terms, see the file COPYING in this directory.
-.TH popclient LOCAL
+.TH fetchmail LOCAL
.SH NAME
-popclient \- retrieve mail from a mailserver using Post Office Protocol.
+fetchmail \- retrieve mail from a mailserver using POP2, POP3, APOP, or IMAP
.SH SYNOPSIS
-.B popclient
+.B fetchmail
[\fI options \fR] \fI [server-host...]\fR
.SH DESCRIPTION
-.I popclient
-is a Post Office Protocol compliant mail retrieval client which supports
-both POP2 (as specified in RFC 937) and POP3 (RFC 1725).
-.PP
-Typically,
-.I popclient
-will be used to download mail in batch from the remote mailserver specified by
-.I host
-to a mail folder on the local disk. The retrieved mail can then be
-manipulated using a local mail reader, such as
-.I mail
-or
-.I elm.
-.PP
-To facilitate the use of
-.I popclient
-in scripts, pipelines, etc, it returns an appropriate exit code upon
-termination -- see EXIT CODES below.
+.I fetchmail
+is a batch mail retrieval utility intended to be used over on-demand
+TCP/IP links (such as SLIP or PPP connections). It fetches mail from
+remote mail servers and forwards it to your local (client) machine's
+delivery system, where it can then be be read by normal mail user
+agents such as \fIelm\fR(1) or \fIMail\fR(1).
+.PP
+The
+.I fetchmail
+program can gather mail from servers supporting POP2 (as specified in RFC
+937), POP3 (RFC 1725), IMAP2bis (as implemented by the 4.4BSD imapd
+program), and IMAP4 (RFC1730). It can use (but does not require) the
+RPOP and LAST facilities removed from later POP3 versions.
.PP
The behavior of
-.I popclient
-is controlled by comand-line options and a control file,
-.I ~/.poprc
+.I fetchmail
+is controlled by comand-line options and a run control file,
+.I ~/.fetchmailrc
the syntax of which we describe below. Command-line options override
-.I ~/.poprc
+.I ~/.fetchmailrc
declarations.
+.PP
+To facilitate the use of
+.I fetchmail
+in scripts, pipelines, etc, it returns an appropriate exit code upon
+termination -- see EXIT CODES below.
.SH OPTIONS
Each server name that you specify (following the options on the
command line) will be queried. If you don't specify any servers
on the command line, each server in your
-.I ~/.poprc
-file will be operated on.
+.I ~/.fetchmailrc
+file will be queried.
.TP
.B \-2
Use Post Office Protocol version 2 (POP2). See also the
POP3 only. Retrieve both old (previously retrieved) and new messages from
the mailserver.
.TP
+.B \-S host, --smtphost host
+Specify an SMTP forwarding host (other than localhost). Normally
+fetched mail is delivered by SMTP over a socket to the client machine
+.I fetchmail
+is running on (this simulates the way mail would
+be delivered to the client by a normal Internet TCP/IP connection).
+With this option you can specify another host to deliver to.
+.TP
+.B \-m mda, --mda mda
+Specify a mail delivery agent to use. See OUTPUT OPTIONS below for a
+complete description.
+.TP
+.B \-o folder, --local folder
+Causes retrieved messages to be appended to file named by the folder
+argument. See OUTPUT OPTIONS below for a complete description.
+.TP
.B \-c, --stdout
Causes retrieved messages to be written to stdout instead of a mail folder.
See OUTPUT OPTIONS below for a complete description. You may not specify
options on the same command line.
.TP
.B \-F, --flush
-POP3 only. Delete old (previously retrieved) messages from the mailserver
+POP3/IMAP only. Delete old (previously retrieved) messages from the mailserver
before retrieving new messages.
.TP
-.B \-f pathname, --poprc pathname
-Specify an alternate name for the .poprc file.
+.B \-f pathname, --fetchmailrc pathname
+Specify an alternate name for the .fetchmailrc run control file.
.TP
.B \-k, --keep
Keep retrieved messages in folder on remote mailserver. Normally, messages
are deleted from the folder on the mailserver after they have been retrieved
(unless
-.I popclient
+.I fetchmail
was compiled with the KEEP_IS_DEFAULT option). Specifying the
.B keep
option causes retrieved messages to remain in your folder on the mailserver.
.TP
.B \-K, --kill
Delete retrieved messages from the remote mailserver. If
-.I popclient
+.I fetchmail
is compiled with the KEEP_IS_DEFAULT option, the
.B kill
option forces retrieved mail to be deleted.
.TP
.B \-l lines, --limit lines
-POP3 only. Retrieve no more than the specified number of lines of each
-message body (plus message headers). The
+POP3 and IMAP only. Retrieve no more than the specified number of
+lines (POP3) or characters (IMAP) of each message body (plus message
+headers). The
.B keep
option is implied by the
.B limit
.B limit
option remain on the remote mailserver.
.TP
-.B \-m mda, --mda mda
-Specify a mail delivery agent to use. This can be used to pass
-fetched mail to programs like procmail. If the MDA string contains
-%s, that escape will be expanded into your username on the client
-machine. Some possible MDAs are "/usr/formail", "/usr/bin/deliver %s",
-"/usr/lib/sendmail -oem -t - -q %s".
-.TP
-.B \--protocol proto
+.B \-p, \--protocol proto
Specify the protocol to used when communicating with the remote
-mailserver.
+mailserver. If no protocol is specified,
+.I fetchmail
+will try each of the supported protocols in turn, terminating after
+any successful attempt.
.I proto
may be one of the following:
.RS
-.IP POP2
+.IP IMAP
+IMAP2bis, a compatible subset of IMAP4.
+.IP POP2
Post Office Protocol 2
.IP POP3
Post Office Protocol 3
.IP APOP
Use POP3 with MD5 authentication.
-.IP RPOP
-Use POP3 with trusted-host-based authentication (like rlogin/rsh).
-.I popclient
-must be installed as a setuid root program to use RPOP.
-.B \--proto.
.RE
.TP
-.B \-o folder, --local folder
-Causes retrieved messages to be appended to file named by the folder
-argument. When neither
-.B \-o
-nor
-.B \-c
-is specified, retrieved messages are appended to the system default mail
-folder. See OUTPUT OPTIONS below for a complete description.
+.B \-P, --port
+The option permits you to specify a TCP/IP port to connect on. You
+will need to specify this in order to use RPOP authentication. Otherwise
+this option will seldom be necessary as all the supported protocols have
+well-established default port numbers.
.TP
.B \-r folder, --remote folder
-Causes an alternate mail folder on the mailserver to be retrieved. The
-syntax of the folder name is server dependent, as is the default behavior
-when no folder is specified. Fortunately, most POP servers have a reasonable
-default behavior, so use of this option should be limited to fairly specialized
-applications. POP3 does not provide a folder specification in the protocol.
+Causes an alternate mail folder on the mailserver to be retrieved.
+The syntax of the folder name is server dependent, as is the default
+behavior when no folder is specified. Fortunately, most POP2 and IMAP
+servers have a reasonable default behavior, so use of this option
+should be limited to fairly specialized applications. POP3 does not
+support a folder specification in the protocol.
If the
.B remote
option is used in conjunction with the POP3 protocol, the remote folder
.TP
.B \-u name, --username name
Specifies the user idenfication to be used when logging-in to the mailserver.
-The appropriate user identification is both server and user dependent.
+The appropriate user identification is both server and user-dependent.
The default is your login name on the machine that is running
-.I popclient.
+.I fetchmail.
See USER AUTHENTICATION below for a complete description.
.TP
.B \-v, --verbose
Verbose mode. All control messages passed between
-.I popclient
+.I fetchmail
and the mailserver are echoed to stderr. Specifying
.B verbose
causes normal progress/status messages which would be redundant or meaningless
to be modified or omitted.
.TP
+.B \-N, --norewrite
+Normally,
+.I fetchmail
+edits RFC-822 address headers (To, From, Cc, Bcc, and Reply-To) in
+fetched mail so that any mail IDs local to the server are expanded to
+full addresses (@ and the POP host name are appended). This enables
+replies on the client to get addressed correctly (otherwise your
+mailer might think they should be addressed to local users on the
+client machine). This option disables the rewrite.
+.TP
.B \-V, --version
Displays the version information for your copy of
-.I popclient.
+.I fetchmail.
No POP connection is made.
Instead, for each server specified, all option information
that would be computed if
-.I popclient.
+.I fetchmail.
were connecting to that server is displayed.
.TP
-.PP
-.SH PROTOCOL SELECTION
-The selection of the correct Post Office Protocol (POP2 or POP3) depends upon
-the configuration of the mailserver from which you retrieve your mail. The
-system adminstrator who installed
-.I popclient
-on your system should have chosen an appropriate default protocol for your
-mailserver. If you get the message 'Connection refused' when using the
-default protocol, try specifying
-.B \-2
-or
-.B \-3
-to select a different protocol. If the 'Connection refused' message persists
-regardless of the protocol selected, it is likely that your mailserver is not
-running a POP compliant mail service.
-.PP
.SH USER AUTHENTICATION
User authentication in
-.I popclient
+.I fetchmail
is very much like the authentication mechanism of
.I ftp(1).
The correct user-id and password depend upon the underlying security
.PP
If the mailserver is a Unix machine on which you have an ordinary user
account, your regular login name and password are used with
-.I popclient.
+.I fetchmail.
If you use the same login name on both the server and the client machines,
you needn't worry about specifying a user-id with the
.B \-u
.B \-u
option. e.g. if your login name is 'jsmith' on a machine named 'mailgrunt',
you would start
-.I popclient
+.I fetchmail
as follows:
.IP
-popclient -u jsmith mailgrunt
+fetchmail -u jsmith mailgrunt
.PP
The default behavior of
-.I popclient
+.I fetchmail
is to prompt you for your mailserver password before the POP connection is
established. This is the safest way to use
-.I popclient
+.I fetchmail
and ensures that your password will not be compromised. You may also specify
your password in your
-.I ~/.poprc
+.I ~/.fetchmailrc
file. This is convenient when using
-.I popclient
-with automated scripts.
+.I fetchmail
+in daemon mode or with scripts.
.PP
On mailservers that do not provide ordinary user accounts, your user-id and
password are usually assigned by the server administrator when you apply for
a mailbox on the server. Contact your server administrator if you don't know
the correct user-id and password for your mailbox account.
.PP
+POP3 versions up to the RFC1225 version supported an alternate
+authentication mechanism called RPOP intended to remove the security
+risk inherent in sending unencrypted account passwords across the net
+(in RFC1460 this facility was replaced with APOP). If you specify the
+RPOP protocol and a connection port in the privileged range (1..1024),
+.I fetchmail will
+ship your password entry to the mail server as an RPOP id.
+(Note: you'll need to be running fetchmail setuid root for RPOP to
+work --
+.I fetchmail
+has to bind to a privileged port locally in order for the mail
+server to believe it's allowed to bind to a privileged remote port.)
+.PP
+RFC1460 introduced APOP authentication. In this variant of POP3,
+you register an APOP password on your server host (the program
+to do this with on the server is probably called \fIpopauth\fR(8)). You
+put the same password in your
+.I .fetchmailrc
+file. Each time
+.I fetchmail
+logs in, it sends a cryptographically secure hash of your password and
+the server greeting time to the server, which can verify it by
+checking its authorization database.
+.PP
.SH OUTPUT OPTIONS
-.I popclient
-always writes the retrieved messages using Unix mail folder format. This
-allows
-.I popclient
-to be used in conjunction with common mail readers like
-.I mail
-and
-.I elm.
-The retrieved messages are normally appended to your default system
-mailbox on the local disk, so that when you invoke your mail reader it
-can manipulate the retrieved messages like any other mail you receive
-on the client machine. If
-.I popclient
-doesn't know where your mailbox is, or can't modify it safely (e.g. because
-your underlying operating system doesn't support mandatory file
-locking), it will use the local Mail Delivery Agent
-(MDA), usually
-/bin/mail(1),
+The default behavior of
+.I fetchmail
+is to ship mail via SMTP to port 25 on the machine it is running on
+(localhost), just as though it were being passed in over a normal TCP/IP link.
+This normally results in the mail being delivered locally via your
+system's default MDA (Mail Delivery Agent, usually
+.I /usr/lib/sendmail
+but your system may use a different MDA).
+.PP
+You can force mail to be passed to an MDA directly with the -mda or -m
+option. Some possible MDAs are "/usr/lib/sendmail -oem %s",
+"/usr/formail", and "/usr/bin/deliver %s" (if the MDA string contains
+%s, that escape will be expanded into your username on the client
+machine). This shouldn't be necessary unless for some reason you
+want to bypass your system's default MDA.
.PP
Using the
.B \-o
-option, you can specify a different mail folder to which the retrieved
-messages will be appended. If you prefer, for example, to have your POP
+option, you can specify a mail folder to which retrieved
+messages will be appended;
+.I fetchmail
+always writes the retrieved messages using Unix mail folder format so
+the folder will be parsed correctly by Unix mail programs such as
+.I elm
+or
+.I pine.
+.PP
+If you prefer, for example, to have your POP
mail from a machine called 'mailgrunt' stored in the
.I mbox
file in your home directory, you would start
-.I popclient
+.I fetchmail
as follows:
.IP
-popclient \-o $HOME/mbox mailgrunt
+fetchmail \-o $HOME/mbox mailgrunt
.PP
Note that the folder specified with
.B \-o
-is write-locked while popclient is writing to it,
+is write-locked while fetchmail is writing to it,
.PP
-.I popclient
+.I fetchmail
can be used in a shell pipeline by using the
.B \-c
option. In this mode,
-.I popclient
+.I fetchmail
writes the retrieved messages to stdout, instead of a mail folder. This would
allow you, for instance, to pass the incoming mail through a filter that
discards mail marked as 'Precedence: junk'. Suppose you've written an AWK
and write it to a folder called 'realmail' in your home directory would be:
.nf
- popclient -c mailgrunt | awk -f dumpjunk.awk >$HOME/realmail
+ fetchmail -c mailgrunt | awk -f dumpjunk.awk >$HOME/realmail
.fi
.PP
The progress/status messages written to stderr when the
does not function incorrectly. The safest bet would be something like:
.nf
- popclient -k -c mailgrunt | myfilter >$HOME/filtered.mail
+ fetchmail -k -c mailgrunt | myfilter >$HOME/filtered.mail
.fi
.PP
followed by
.nf
- popclient -c mailgrunt > /dev/null
+ fetchmail -c mailgrunt > /dev/null
.fi
.PP
when you're sure the messages were correctly processed by 'myfilter'.
or
.B -d
option runs
-.I popmail
+.I fetchmail
in daemon mode. You must specify a numeric argument which is a
polling interval in seconds.
.PP
In daemon mode,
-.I popmail
+.I fetchmail
puts itself in background and runs forever, querying each specified
host and then sleeping for the given polling interval.
.PP
Simply invoking
.IP
-popmail -d 900
+fetchmail -d 900
.PP
will, therefore, poll the hosts described in your
-.I ~/.poprc
+.I ~/.fetchmailrc
file once every fifteen minutes.
.PP
Only one daemon process is permitted per user; in daemon mode,
-.I popclient
+.I fetchmail
makes a per-user lockfile to guarantee this. The option
.B --quit
will kill a running daemon process.
-.SH THE POPRC FILE
-The preferred way to set up popclient (and the only way if you want to
-specify a password) is to write a .poprc file in your home directory.
-To protect the security of your passwords, your ~/.poprc may not have
+.PP
+The
+.B -L
+or
+.B --logfile
+option allows you to redirect status messages emitted while in daemon
+mode into a specified logfile (follow the option with the logfile name).
+This is primarily useful for debugging configurations.
+.SH THE RUN CONTROL FILE
+The preferred way to set up fetchmail (and the only way if you want to
+specify a password) is to write a .fetchmailrc file in your home directory.
+To protect the security of your passwords, your ~/.fetchmailrc may not have
more than u+r,u+w permissions;
-.I popclient
+.I fetchmail
will complain and exit otherwise.
.PP
Comments begin with a '#' and extend through the end of the line.
remotefolder (or remote)
localfolder (or local)
mda
+ smtphost (or smtp)
keep
flush
fetchall
+ rewrite
+ skip
nokeep
noflush
nofetchall
+ norewrite
+ noskip
+ port
+.PP
+All these correspond to the obvuious command-line arguments except
+two: \fBpassword\fR and \fBskip\fR.
+.PP
+The \fBpassword\fR option requires a string argument, which is the password
+to be used with the entry's server.
+.PP
+The \fBskip\fR option tells
+.I fetchmail
+not to query this host unless it is explicitly named on the command
+line. A host entry with this flag will be skipped when
+.I fetchmail
+called with no arguments steps through all hosts in the run control file.
+(This option allows you to experiment with test entries safely.)
.PP
Legal protocol identifiers are
+ auto (or AUTO)
pop2 (or POP2)
pop3 (or POP3)
imap (or IMAP)
.nf
server pop.provider.net \e
proto pop3 \e
+ port 3111 \e
user jsmith \e
pass secret1 \e
localfolder ~/mbox
.fi
-If you need to include whitespace in a paramter string, enclose the
+If you need to include whitespace in a parameter string, enclose the
string in double quotes. Thus:
.nf
proto pop3 \e
user jsmith \e
pass secret1 \e
- mda "/bin/mail -d %s"
+ mda "/bin/mail %s"
.fi
Finally, you may have an initial server description headed by the keyword
`defaults' instead of `server' followed by a name. Such a record
defaults \e
proto pop3 \e
user jsmith \e
- mda "/bin/mail -d %s"
+ mda "/bin/mail %s"
server pop.provider.net \e
pass secret1 \e
server mail.provider.net \e
.fi
.SH EXIT CODES
To facilitate the use of
-.I popclient
+.I fetchmail
in shell scripts and the like, an exit code is returned to give an indication
of what occured during a given POP connection. The exit code can be tested
by the script and appropriate action taken.
.PP
A simple example follows. This Bourne shell script executes
-.I popclient
+.I fetchmail
and, if some messages were successfully retrieved from a mailserver retrieved
from the command line, it starts the
.I mail
.EX 0
#!/bin/sh
-if popclient $1
+if fetchmail $1
then
mail
else
.EE
.PP
The exit codes returned by
-.I popclient
+.I fetchmail
are as follows:
.IP 0
One or more messages were successfully retrieved.
just treat this as an 'unrecoverable error'.
.IP 3
The user authentication step failed. This usually means that a bad
-user-id or password was specified.
+user-id, password, or RPOP id was specified.
.IP 4
-Some sort of protocol error was detected. POP is not especially forgiving
-when it comes to unexpected responses, commands, etc -- the protocol invariably
-calls for terminating the connection under such error conditions.
+Some sort of fatal protocol error was detected.
.IP 5
There was a syntax error in the arguments to
-.I popclient.
+.I fetchmail.
.IP 6
Some kind of I/O woes occurred when writing to the local folder.
.IP 7
There was an error condition reported by the server (POP3 only).
.IP 8
Exclusion error. This means
-.I popclient
+.I fetchmail
either found another copy of itself already running, or failed in such
a way that it isn't sure whether another copy is running.
.IP 9
+The
+.I fetchmail.
+run failed while trying to do an SMTP port open or transaction.
+.IP 10
Something totally undefined occured. This is usually caused by a bug within
-.I popclient.
+.I fetchmail.
Do let me know if this happens.
.PP
When
-.I popclient
+.I fetchmail
queries more than one host, the returned status is that of the last
host queried.
.SH AUTHOR
-.I popclient
-was written by Carl Harris at Virginia Polytechnic Institute and State
-University (a.k.a. Virginia Tech). Version 3.0 was extensively hacked
-by Eric S. Raymond <esr@snark.thyrsus.com>.
-.PP
-.SH BUGS
-.PP
-The --version option doesn't display MDA arguments.
-.PP
-No IMAP or RPOP support yet.
-.PP
-Send comments, bug reports, gripes, and the like to ceharris@mal.com.
+.I fetchmail
+was originated (under the name `popclient') by Carl Harris at Virginia
+Polytechnic Institute and State University (a.k.a. Virginia Tech).
+Version 3.0 of popclient was extensively rewritten and improved by
+Eric S. Raymond <esr@snark.thyrsus.com>. The program's name was
+then changed to
+.I fetchmail
+to reflect both the presence of IMAP support and the symmetry with sendmail
+created by the new SMTP forwarding default.
+.PP
+.SH FILES
+.TP 5
+~/.fetchmailrc
+default run control file
+.TP 5
+${TMPDIR}/fetchmail-${HOST}-${USER}
+lock file to help prevent concurrent runs.
+.SH ENVIRONMENT
+For correct initialization,
+.I fetchmail
+requires either that both the USER and HOME environment variables are
+correctly set, or that \fBgetpwuid\fR(3) be able to retrieve a password
+entry from your user ID.
+.SH KNOWN PROBLEMS
+Use of any of the supported protocols other than APOP requires that
+the program send unencrypted passwords over the TCP/IP connection to
+the mail server. This creates a risk that name/password pairs might
+be snaffled with a packet sniffer or more sophisticated monitoring
+software.
+.pp
+Running more than one concurrent instance of
+.I fetchmail
+on the same mailbox may cause messages to be lost or remain unfetched.
+(This is a design problem of the POP2, POP3 and IMAP2bis protocols.)
+.PP
+If, using POP3, you find that messages you've already read on the
+server are being fetched, blame RFC1725. That late version pf the
+POP3 protocol specification ill-advisedly removed the LAST command, and
+some servers (including the one distributed with at least some
+versions of SunOS) follow it (you can verify this by invoking
+.I fetchmail -v
+and watching the response to LAST early in the query). The fix is to
+install an older POP3 server with LAST or switch to an IMAP server.
+.PP
+The RPOP support is not yet well tested.
+.PP
+Send comments, bug reports, gripes, and the like to Eric S. Raymond
+<esr@thyrsus.com>.
.SH NOTE
-The -p (--password) option of previous versions has been removed -- it
+This program used to be called `popclient' (the name was changed
+because it supports IMAP now and may well support more remote-fetch
+protocols such as DMSP in the future).
+.PP
+The --password option of previous (popclient) versions has been removed -- it
encouraged people to expose passwords in scripts. Passwords
-must now be specified either manually or in your
-.I ~/.poprc
-file.
+must now be specified either interactively or in your
+.I ~/.fetchmailrc
+file. The short-form -p option now specifies the protocol to use.
+.PP
+The reason the password isn't stored encrypted is because this doesn't
+actually add protection. Anyone who's acquired permissions to read your
+fetchmailrc file will be able to run
+.I fetchmail
+as you anyway -- and if it's
+your password they're after, they'd be able to use the necessary decoder from
+.I fetchmail
+itself to get it. All encryption would do in this context is give a
+false sense of security to people who don't think very hard.
.SH SEE ALSO
-mail(1), binmail(1), sendmail(8), popd(8), RFC 937, RFC 1225.
+mail(1), binmail(1), sendmail(8), popd(8), imapd(8)
+RFC 937, RFC 1081, RFC 1082, RFC 1225, RFC 1460, RFC 1725.