POSTOFFICE.CF(5)

NAME
postoffice.cf - configuration file for postoffice

SYNOPSIS
postoffice.cf

DESCRIPTION
This file resides in @confdir@, and contains various configuration options for the postoffice mail server. All of the options listed here can also be passed directly to the postoffice server via the -o command line option.

The format of the configuration file is one option per line, with blank lines and lines beginning with # ignored as comment lines. The options are:

audit
    Enable session auditing.

checkhelo
    Check the arguments passed with the HELO and EHLO SMTP command and refuse to do an SMTP conversation with the client if they claim to be the mail server.

clients=N
    Allow only N clients at a time to connect to the server.

debug
    Enable the ESMTP ‘DEBUG’ command, which displays various compile and runtime settings, as well as the current state of the mail envelope.

delay=N
    Set the greylisting delay to N seconds. The delay may be specified as a tagged number, with ‘m’ being minutes. and ‘h’ being hours. @MILTERMAN@.It Li filter Ns = Ns Ar socket @MILTERMAN@Defines a sendmail filter that will scan incoming mail @MILTERMAN@before @MILTERMAN@.Nm @MILTERMAN@accepts it. The @MILTERMAN@.Ar socket @MILTERMAN@can be either a Unix-domain socket on the local machine @MILTERMAN@or a tcp socket on a different machine.

forward-all
    When set, forward all unknown mail to the configured relay-host.

hops=N
    Set the hop count to N. The hop count is incremented every time the mail is processed. When it reaches this limit, the mail is returned with an error message (the default is 100 hops).

load=N
    When the load average is above N, postoffice will not accept SMTP connections (the default is 4).

localmx
    Treat connections from sites that use this machine as an MX as if they were local, and give them the permissions that local clients have. @STATFS@.It Li minfree Ns = Ns Ar N @STATFS@Stop accepting mail when there are less than @STATFS@.Ar N @STATFS@kilobytes available on the mail spool volume. @STATFS@.Xr minfree @STATFS@is given as a tagged number, @STATFS@with @STATFS@.Ql m @STATFS@being megabytes, @STATFS@and @STATFS@.Ql g @STATFS@being gigabytes

nodaemon
    Do not accept mail from <>. This can be useful for blocking spammers and viruses, but it also violates and means that nobody at your site (including mailing lists) will ever get bounce messages when mail cannot be delivered. If your machine is connected to a public network, DON'T SET THIS OPTION unless you're under attack from a malicious spammer.

paranoid
    Do not accept mail from sites unless we can resolve their dns address.

qreturn=N
    Bounce undeliverable mail after N seconds. The qreturn may be specified as a tagged number, with ‘m’ being minutes, ‘h’ being hours, and ‘d’ being days.

relay
    Allow all clients to relay mail through this server. If your machine is connected to a public network, DON'T SET THIS OPTION, unless you really want to end up on every antispam blacklist on the planet.

relay-host=host
    Send all mail destined for remote hosts via this host. The superuser is the only user that can use this option on the command line or in a configuration file other than /etc/postoffice.cf

self=host
    Set our hostname to host. Postoffice normally uses the uname() system call to determine the machine name, but you can set it to just about anything here.

size=size
    Sets the largest message size that postoffice will accept. size is given as a tagged number, with ‘k’ being kilobytes, and ‘m’ being megabytes.

soft-deny
    If set, refuse blacklisted and paranoid connections with a 4xx (temporary) error status instead of the normal 5xx (permanent) errors.

timeout=timeout
    Drop the connection to a client if they are idle longer than timeout. This option violates the word (if not the intent) of the SMTP specification, so the timeout should probably be fairly large. The timeout may be specified as a tagged number, with ‘m’ being minutes, ‘h’ being hours, and ‘d’ being days. For example, ‘timeout=60m’ or ‘timeout=1h’ both set the timeout to one hour.

verify-from=flag
    Check the validity of MAIL FROM addresses. If nonzero (the default), the address will be rejected if it's from an unresolvable domain or if a remote client attempts to give a local address, and if zero, anything the client gives is okay with postoffice.

SEE ALSO
postoffice(8)