2.17 Hints

a new sendmail.cf file

Requires that you restart the sendmail daemon, or else the daemon will not know of the changes. Before installing a new configuration file be sure to test it with the -C command-line switch. When using -C for testing, also use -oQ/tmp.

$=w and MX records

Require that any host that lists your host as the best MX record be included in your hosts' $=w class declaration, or in your sendmail.cw file.

F=m and quotas

Don't combine well. If one user is over quota, /bin/mail cannot tell if one or all recipients of a multi-recipient message failed, so it exits in a way that causes sendmail to retry delivery to all the recipients over and over again. If you run quotas on the mail spool directory, try disabling the F=m flag for the local delivery agent.