Exim is the standard mail-server of the majority of Linux distributions. Typically, it requires minimal maintenance, but when configuring it, or occasionally when something goes wrong, you have to intervene. Here are a few useful Exim commands:

Get the version of Exim:

exim -bV

Testing

Check the routing of an email address:

exim -bt <user>
exim -bt <user>@<local-domain>
exim -bt <user>@<domain>

Note: To ignore a scanner add the no_address_test flag to the router for that scanner.

To test an SMTP session as if from a specific IP:

exim -d -bh 127.0.0.1

Managing Queues

List messages in the queue (optionally restrict to specific sender and/or receiver:

exiqgrep [-f <user>@<domain>] [-r <user>@<domain>]

Delete frozen messages (-z) from the queue:

exiqgrep -z -i | xargs exim -Mrm

The -i requests just the MessageID from exiqgrep.