countmail - be obnoxious about how much mail you have
The countmail program counts your mail and tells you about it rather
The countmail program first appeared in NetBSD 1.3. countmail was first
written by Noah Friedman 〈email@example.com〉 in 1993. This version was
written by Charles M. Hannum 〈mycroft@NetBSD.org〉.
The read loop is horrendously slow on every shell implementation tried.
countmail uses from(1) and wc(1) instead, though these are not shell