Telnet is not outdated at all, and in fact I use telnet to debug mail problems at work every day.
You have to read RFC 821
and also RFC 2821
which succeeded it.
Don't forget to say HELO/EHLO to the server. I've come across some wierd and rude replies from servers that aren't greeted properly first.
CEH, CCSA NG/AI, NNCSS, MCP, MCSA 2003
There are 10 kinds of people, those that understand binary, and those that don't.