README revision 96210 
1# $FreeBSD: head/etc/mail/README 96210 2002-05-08 05:17:46Z gshapiro $
2
3		Sendmail Processes
4
5As of sendmail 8.12, in order to improve security, the sendmail binary no
6longer needs to be set-user-ID root.  Instead, a set-group-ID binary
7accepts command line mail and relays it to a full mail transfer agent via
8SMTP.  A group writable client mail queue (/var/spool/clientmqueue/ by
9default) holds the mail if an MTA can not be contacted.
10
11To accomplish this, under the default setup, an MTA must be listening on
12localhost port 25.  If the rc.conf sendmail_enable option is set to "NO",
13a sendmail daemon will still be started and bound only to the localhost
14interface in order to accept command line submitted mail.  If this is not
15a desirable solution, it can be disabled using the sendmail_submit_enable
16rc.conf option.  However, if both sendmail_enable and sendmail_submit_enable
17are set to "NO", you must do one of two things for command line submitted
18mail:
19
201. Designate an alternative host for the submission agent to contact
21   by altering /etc/mail/freebsd.submit.mc (or setting SENDMAIL_SUBMIT_MC
22   in /etc/make.conf to an alternate .mc file) and using
23   'make install-submit-cf' in /etc/mail/.  Change the FEATURE(msp) line
24   to FEATURE(msp, hostname) where hostname is the fully qualified hostname
25   of the alternative host.
26
27Or:
28
292. Return to using a set-user-ID root sendmail binary by changing the
30   ownership and permissions on the sendmail binary and removing the
31   /etc/mail/submit.cf file:
32	chown root /usr/libexec/sendmail/sendmail
33	chmod 4755 /usr/libexec/sendmail/sendmail
34	rm /etc/mail/submit.cf
35   If you install from source, set the SENDMAIL_SET_USER_ID flag in
36   /etc/make.conf.
37
38Also, as of 8.12, a new queue-running daemon is started to make sure mail
39doesn't remain in the client mail queue.  By default, it simply runs the
40client mail queue every 30 minutes.  Its behavior can be adjusted by setting
41the sendmail_msp_queue_enable and sendmail_msp_queue_flags rc.conf options.
42
43
44		Filtering out SPAM from your site
45
46Sendmail now includes excellent tools to block spam.  These tools are
47available as FEATUREs that you can add to your site's .mc file.  Proper use
48of these FEATUREs will prevent spammer from using your site as a relay as
49well as significantly decrease the amount of spam that arrives at your
50site.  No set of anti-spam tools will block all spam without blocking some
51portion of legitimate mail as well.  Therefore, these FEATUREs are designed
52to prevent as much spam as possible without blocking legitimate mail.
53
54These tools are discussed in /usr/share/sendmail/cf/README.  Read the
55section entitled "ANTI-SPAM CONFIGURATION CONTROL".  Example usage and
56additional tools can be found in /usr/share/sendmail/cf/cf/knecht.mc.
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