On Tuesday 23 Sep 2003 17:33, you wrote:

> I've gotten three messages over the past few days with the title line
> "undeliverable message" and the text saying that "we were unable to send
> your message tot he following address" with different addresses each
> time.

It's a virus. The message is designed to entice you to open it and run the
attachment - which some (MS) software will do automatically, if not
configured properly OR used in its default configuration.
--
Tim
PGP Key ID: 525e6a47
Available from http://pgp.mit.edu