Forging E-Mail addresses

Well I was going through my old MacAddict and I found this old issue from April, 2001. It had 10 things you shouldn't do (cause they are wrong). I remember reading this back in the day and it had one thing that I never tried an that was forging e-mails. It explains all you need to do is get into a SMTP server via Telneting a server on port 25. My friends and I want to have some fun with this so I've been playing around with it.

Either I am doing something wrong or the SMTP servers I am using won't work. I am also thinking better security measures have been put into affect since 2001.

Anyone ever try this or have some insight. I am probably doing something wrong since the Terminal and things like that aren't not my best subjects.

jon