Invalid E-mail addresses

From: Stephanie Wong <>
Subject: Invalid E-mail addresses
Date: Sun, 7 Dec 1997 20:50:59 -0700 (MST)

Sometimes, I get mail returns for invalid E-mail addresses subscribed to
this list.  It is quite annoying sometimes when you keep on getting
"Returned mail: Cannot send message within 3 days".  Is there any software
to stop this?