1.5 Hints

/usr/lib/sendmail -bv list | grep -v deliverable

Causes sendmail to recursively expand the addresses in the mailing list named list. The -v with grep(1) causes all good (deliverable) addresses to be excluded and only bad addresses to be printed.

/usr/lib/sendmail -bt -d0.4 </dev/null

Causes sendmail to print its version, the #defines used when it was compiled, and how it is interpreting the identity of the local machine.

mailq -OMaxQueueRunSize=1

Allows sendmail to quickly print how many messages are queued even when the queue contains thousands of messages.

/usr/lib/sendmail -q -OTimeout.queuereturn=99d

Flushes messages from an old queue (perhaps following a prolonged downtime) while preventing old messages from timing out in the queue.