What was the "P" for? perl? Queue Perl Daemon? Drop smtp and that's "qpd".
Along the same lines, you could do Perl Queue(ing) Daemon (pqd), or Quick Perl Queuing Daemon (qpqd) for Matt's high perf stuff. Or heck, even Quench the Perl Queuing Daemon. Quite a few hits (85K) for pqd, but far fewer (1.4K, most of them non-English) for qpqd. And neither one is a mouthful to say.
-- Bryan