pfqueue provides a console (ncurses) interface to Postfix 1, Postfix 2 and
Exim mail queues.
It is a real-time queue scanner that shows per-queue lists of existing
messages; the messages can be deleted, put on hold or released.
For example, it may be useful to inspect a traffic jam at a given time, to see
what is falling into and unexpectedly crowding your deferred queue.