Red Hat Enterprise Linux 5 Administration Unleashed

Configuring Sendmail 371. local-host-names. mailertableIf the email server should be known by different hostnames, list the hostnamesin this file, one line per hostname. Any email sent to addresses at thesehostnames is treated as local mail. The FEATURE(`use_cw_file’) option mustbe enabled in the sendmail.mc file for this file to be referenced.Table of domains and what mailer and domain they should be routed to.FEATURE(`mailertable’) must be enabled in sendmail.mc.. trusted-usersList of users that can send email as other users without a warning includingsystem users such as apache for the Apache HTTP Server.. virtusertableList of email address or domain names (meaning all email addresses at thatdomain) along with an email address to forward them to or an error code toreturn for the email address.TIPFurther details about all these files can be found in /usr/share/doc/sendmail/README.cf from the sendmail-docs package.Some of these configuration files are similar to sendmail.mc and submit.mc in that they arenot the actual files referenced by Sendmail. If the access, domaintable, mailertable, orvirtusertable file is modified, the corresponding database file referenced by Sendmailmust be regenerated. When the service sendmail {start,reload,restart} command isexecuted, the initialization script calls the makemap utility to regenerate these database files.An additional configuration file, /etc/aliases, can be used to redirect email from oneuser to another. By default, it includes redirects for system accounts to the root user. Itcan then be used to redirect all email for the root user to the user account for the systemadministrator. If this file is modified, the Sendmail service must be restarted so that theinitialization script runs the newaliases utility to rebuild the aliases database referencedby Sendmail.18By default, Sendmail in Red Hat Enterprise Linux is configured to only accept connectionsfrom the local system through the loopback device (127.0.0.1). To modify this behavior,locate the following line in /etc/mail/sendmail.mc:DAEMON_OPTIONS(`Port=smtp,Addr=127.0.0.1, Name=MTA’)dnlEither comment out the line completely by prepending it with dnl and a space or bychanging the loopback address (127.0.0.1) to the IP address of the network device listeningfor Sendmail connections.