How do I delete all Terminal mail? I set up a cronjob a long time ago that now doesn't exist. Whenever I open up Terminal, it now says "You have mail". I have something like 100 messages that all say the same thing. How do I mass delete all of the messages?
Launch the UNIX mail utility by running the following at the command prompt (in e.g. Terminal.app):
$ mail

You'll see a list of all your messages. From the mail prompt, do
? delete *
? q

And that should be it. Make sure do to the q after the delete * command, that saves the changes to disk.