that uses the sendmail Mail Transport Agent (MTA).
* mailqs reads the output from sendmail's mailq(8) command and summarizes
each queue entry, one entry per line. As such, its output is more easily
consumed by other scripts.
* rmmq is a convenience command for removing items from a sendmail queue.
When you run mailq(8) or mailqs, you get a list of sendmail queue IDs.
These queue IDs map to several files in a sendmail queue directory. This
command automatically maps the queue IDs to the files and removes them for you.
(imported from pkgsrc-wip)