System Administration Guide: Network Services

How to Check Mail Aliases

The following example shows you how to verify an alias.

% mconnect
connecting to host localhost (, port 25
connection open
220 ESMTP Sendmail 8.13.6+Sun/8.13.6; Tue, 12 Sep 2004 13:34:13 -0800 (PST)
expn sandy
250 2.1.5 <>
221 2.0.0 closing connection

In this example, the mconnect program opened a connection to a mail server on a local host and enabled you to test that connection. The program runs interactively, so you can issue various diagnostic commands. For a complete description, see the mconnect(1) man page. The entry, expn sandy, provided the expanded address, Thus, you have verified that mail can be delivered when using the alias sandy.

Remember to avoid loops and inconsistent databases when both local and domain-wide aliases are used. Be especially careful to avoid the creation of alias loops when you move a user from one system to another system.