Red Hat LINUX 7.2 Reference Manual page 265

Section 16.3:Sendmail
edit the /etc/mail/sendmail.mc file and use the included m4 macro processor to create a
new /etc/sendmail.cf (after backing up the original /etc/sendmail.cf, of course).
More information on configuring Sendmail can be found in Section 16.3.4, Common Sendmail
Configuration Changes.
Various Sendmail configuration files are installed in /etc/mail including:
• access — Specifies which systems can use Sendmail for relaying email.
• domaintable — Allows you to provide domain name mapping.
• local-host-names — The place where you include all aliases for your machine.
• mailertable — Specifies instructions that override routing for particular domains.
• virtusertable — Permits you to do a domain-specific form of aliasing, allowing multiple
virtual domains to be hosted on one machine.
Several of the configuration files in /etc/mail, such as access, domaintable, mail-
ertable and virtusertable, must actually store their information in database files before
Sendmail can use any configuration changes. To include any changes you make to these config-
urations in their database files, you must run the makemap hash /etc/mail/ <name> <
/etc/mail/ <name> command, where <name> is the name of the configuration file to convert.
For example, if you want all email addressed to any domain.com account to be delivered to
bob@otherdomain.com, you need to add a line to the virtusertable file:
Figure 16–1 virtusertable example
@domain.com
Then, to add this new information to the virtusertable.db file, execute makemap hash
/etc/mail/virtusertable < /etc/mail/virtusertable as root. This will create a
new virtusertable.db that contains the new configuration.
16.3.4 Common Sendmail Configuration Changes
A default sendmail.cf file will be installed in /etc. The default configuration should work for
most SMTP-only sites. It will not work for UUCP (UNIX to UNIX Copy) sites; you will need to
generate a new sendmail.cf if you must use UUCP mail transfers.
If you need to generate a new /etc/sendmail.cf file to configure Sendmail, you should utilize
the m4 macro processor. If you ever edit the /etc/mail/sendmail.mc to add functionality to
Sendmail, backup your current /etc/sendmail.cf file, generate a new one by executing the m4
/etc/mail/sendmail.mc > /etc/sendmail.cf command, and add any previous changes
bob@otherdomain.com
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