Linux Network Administrator's Guide, Second Edition

Testing Your Configuration

The m4 command processes the macro definition files according to its own syntax rules without understanding anything about correct sendmail syntax; so there won’t be any error messages if you’ve gotten anything wrong in your macro definition file. For this reason, it is very important that you thoroughly test your configuration. Fortunately, sendmail provides a relatively easy way of doing this.

sendmail supports an “address test” mode that allows us to test our configuration and identify any errors. In this mode of operation, we invoke sendmail from the command line, and it prompts us for a ruleset specification and a destination mail address. sendmail then processes that destination address using the rules specified, displaying the output of each rewrite rule as it proceeds. To place sendmail into this mode, we invoke it with the -bt argument:

# /usr/sbin/sendmail -bt
ADDRESS TEST MODE (ruleset 3 NOT automatically invoked)
Enter <ruleset> <address>
>

The default configuration file used is the /etc/mail/sendmail.cf file; you can specify an alternate configuration file using the -C argument. To test our configuration, we need to select a number of addresses to process that will tell us that each of our mail-handing requirements are met. To illustrate this, we’ll work through a test of our more complicated UUCP configuration shown in Example 18.2.

First we’ll test that sendmail is able to deliver mail to local users on the system. In these tests we expect ...