sendmail Configuration File

A configuration file controls the way that sendmail performs its functions. The configuration file determines the choice of delivery agents, address rewriting rules, and the format of the mail header.

The sendmail program uses the information from the /etc/mail/sendmail.cf file to perform its functions. Each system has a default sendmail.cf file installed in the /etc/mail directory. You do not need to edit or change the default configuration file for mail servers or mail clients. The only systems that require a customized configuration file are mail hosts and mail gateways.

The Solaris operating environment provides two default configuration files in the /etc/mail directory:

1. A configuration file named main.cf for the system (or systems) you designate as the mail host or a mail gateway

2. A configuration file named subsidiary.cf (a duplicate copy of the default sendmail.cf file)

The configuration file you use on a system depends on the role the system plays in your mail service.

• For mail clients or mail servers, you do not need to do anything to set up or edit the default configuration file.

• To set up a mail host or gateway, copy the main.cf file and rename it sendmail.cf (in the /etc/mail directory). Then reconfigure the sendmail configuration file to set the relay mailer and relay host parameters needed for your mail configuration.

The following list describes some configuration parameters you might want to change, depending on the requirements of your site:

• Time values specifies:

  • Read timeouts.

  • Length of time a message remains undelivered in the queue before it is returned to the sender.

• Delivery modes specify how quickly mail will be delivered.

• Load limiting prevents wasted time during loaded periods by not attempting to deliver large messages, messages to many recipients, and messages to sites that have been down for a long time.

• Log level specifies what kinds of problems are logged.