OpenBSD-4.6/etc/mail/README

$OpenBSD: README,v 1.5 2008/09/27 19:17:10 martynas Exp $

This directory contains the configuration files for sendmail(8) and
spamd(8).  The source for the .cf files lives in /usr/share/sendmail/cf.
You should make changes in the corresponding .mc file and not edit
the .cf files directly.  Useful information may be found in
/usr/share/sendmail/README, /usr/share/sendmail/TUNING, and
/usr/share/doc/smm/08.sendmailop/op.me.  For details on enabling
encrypted SMTP, see the starttls(8) man page.

Sendmail configuration files:

    localhost.cf	Built from /usr/share/sendmail/cf/openbsd-localhost.mc.
			Only allows connections from the local host, not
			the network at large.  This is the default
			configuration file used on OpenBSD.  See afterboot(8)
			for more information.

    sendmail.cf		Built from /usr/share/sendmail/cf/openbsd-proto.mc.
			A more full-featured configuration file that
			allows SMTP connections from the internet.

    submit.cf		Built from /usr/share/sendmail/cf/submit.mc.
			Used when sendmail is invoked directly from
			the command line to send mail (for instance,
			when called by mail(1)).

Other files used by sendmail(8) in this directory include:

    access		Access database (blacklist, whitelist, etc).

    aliases		System aliases database.

    genericstable	Used to rewrite the From: line to a generic form.
			Most often used to map login name -> First.Last
			name in outgoing messages.

    helpfile		Help file for sendmail(8).

    local-host-names	List of other hostnames to treat as local.
			You do not need to list the system hostname,
			the name(s) associated with any active network
			interface or a CNAME that points to one of
			those names.  This file is read only at startup
			or when sendmail(8) is sent SIGHUP.

    mailertable		Used to override routing for particular (non-local)
			domains.

    relay-domains	List of other domains to relay mail for.
			By default, sendmail(8) will not relay for
			foreign domains--if the mail is not destined
			for (or sent by) a user in the local domain it
			will be rejected.  This file is read only at
			startup or when sendmail(8) is sent SIGHUP.

    trusted-users	This file contains a list of users (one per
			line) that may set their envelope "from"
			address to a different user via "sendmail
			-f".  Common values include "majordomo",
			"mailman" and "www".  In other words, if a
			daemon (or mailing list manager) sends mail
			purporting to be from a different user, the
			user it runs as should be listed here.  The
			users "root" and "daemon" are implicitly
			included in this list.  This file is read
			only at startup or when sendmail(8) is sent
			SIGHUP.

    virtusertable	Virtual user table; maps incoming mail addresses
			to alternate local usernames or aliases.

Spamd configuration files:

    spamd.conf		The spamd.conf file is read by spamd-setup(8)
			to configure blacklists for spamd(8).
			Blacklists are lists of addresses of likely
			spammers.  Mail from these addresses never
			reaches the actual mail server, but is
			instead redirected to spamd(8) and tarpitted.

Note that by default, only sendmail.cf will use the access, local-host-names,
mailertable, relay-domains, userdb, and virtusertable files.
These files are not used by the default localhost.cf or submit.cf
since they are generally not needed for localhost-only configs.