A handy UNIX command that lists the e-mail that's waiting in the mailbox, printing sender address (not necessarily the From header) and the date. For example:
From email@example.com Tue Sep 12 09:37:12 2000
The format may differ from flavor to flavor, but the basic functionality is the same.
If your flavor doesn't have it (IRIX boxes in here don't have it, at least), a reasonable facsimile goes like this:
grep "^From " $MAIL
assuming the system uses standard mbox format, not some funky format like mh or something. (As for script lisence: take it, it's yours =)
See also: "From " line