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.
Causes sendmail to print its version, the
used when it was compiled, and how it is interpreting the
identity of the local machine.
Allows sendmail to quickly print how many messages are queued even when the queue contains thousands of messages.
Flushes messages from an old queue (perhaps following a prolonged downtime) while preventing old messages from timing out in the queue.