withdrawing mails

[guy at gorodish.UUCP]

>I really hope that a user can withdraw the mails he send such
>that  such mistakes can be cured just like undo in 'vi' or
>backup in file systems.

Well, "undo" in "vi" doesn't go back to the beginning of your session
(and definitely doesn't undo the changes made in a previous editing
session!), and backup tapes don't hang around forever.  Eventually
the mail message gets dumped in the recipient's mailbox, and at that
point it's just too late.  (Even if there were a way to withdraw a
mail message from a mailbox, it doesn't do much good if they've
already read it.)

Mail is very often not queued up for a very long time; mail sent from
my workstation usually makes it to the next hop along the way very
quickly.  Unless the mail routing machine here is loaded, it usually
makes it to its final destination pretty quickly.  The window in
which it would be possible to remove the message from the queue is
just too small to make it worthwhile to provide the ability to do so.