I made this because I couldnt find anything worth adding to the Hacking 101 section on this subject so here we go. Follow the steps below.
First you need a SMTP server, Try searching your ISPs subnet for port 25 “The defualt SMTP port”. If you dont already have a port scanner google one.
Once you have a SMTP server, if your using XP “In vista you have to open a command prompt”, goto the start button then run and in run type:
telnet smtp.ip.addess.here 25
Hit enter, once the window opens you should see some kind of 220 message, thats good. Now type:
MAIL FROM: email@example.com
You should get a 250 ok message, if you get some other message saying something about helo or hello type:
then mail from. Now set the target address by typing:
RCPT TO: firstname.lastname@example.org
If you get some error try another SMTP server.
Hit enter then type: DATA and hit enter again, now start typing your message. At end of message hit enter, then type a “.” by it self w/o the “” and hit enter again. You should get a 250 email sent message. You can test this best by sending a email to your self.
More on spoofing HERE