Let me quickly try to clear up some confusion. I've gotten several replies (real quick response) that are answering a different question. I'm not trying to reimplement TCP/IP. I'm trying to provide a Windows version of NUpop, which is a DOS program that works fine over a simple serial line. Most folks automatically associate SMTP/POP with TCP/IP, but there is no connection. Admittedly they work better with a robust, end to end protocol. But I've been using NUpop for a year over a non-TCP/IP line. I get hundreds of messages a day. It works. But there are no sources available to NUpop, it is a DOS program, and it doesn't support piping messages thru PGP/RIPEM/... I have lots of DOS libraries that do exactly the simple things I need. I don't want to use DOS, I want native Windows code. Pat Pat Farrell Grad Student pfarrell@netcom.com Department of Computer Science George Mason University, Fairfax, VA Public key availble via finger #include <standard.disclaimer>