Second, figure out who you want to be, call that ME. (example: husky)
Third, figure who you want to send mail to, call that person TARGET (example: joe)
Forth, figure what the TARGETs user machine is, and call that TMACHINE (example: mtu.edu)
Now, start the process. (note, bold means you send it to the other computer, and italics means that it's a variable as described above).
For example, to tease a tech student I might
HELO nmu.edu
MAIL FROM:<hockey@nmu.edu>
RCPT TO:<joe@mtu.edu>
DATA
You guys suck. We beet you 8 to 3. We rule!
.
QUIT
And that's all there is folks.