5/30/01: this doesn't work on all sendmail hosts??  the "MAIL" command
wasn't found on a particular sendmail port I attempted this on the other
day (it was a legitimate attempt to spoof an email from an old account
of mine to a listserv so that I could unsubscribe).

tn-gw-> telnet ns.ihub.com 25
Trying 199.29.68.1 port 25...
220 c2smtp.ihub.com Connect2-SMTP 4.10.rc3D (0000001) Ready
HELO FAIRVIEW.ORG
250 c2smtp.ihub.com sez "I'm not wearing any pants, FAIRVIEW.ORG !"
MAIL From: JSTIFTE1@FAIRVIEW.ORG
250 ... Sender Ok
RCPT To: JOKES@INFINITE.ihub.com
250 ... Recipient Ok
DATA
354 It's your nickel pal, end with "." on a new line
Subject: DESUBSCRIBE
.
250 Received 25 characters in 33.50 secs (0 cps)
QUIT
221 c2smtp.ihub.com closing connection, Don't go away mad just go AWAY!!
Remote server has closed connection
Connection closed by foreign host.
is000913:/home/bfr7kq6: