how to send mail using telnet to tcp-port 25

do a telnet on tcp-port 25 to your mail server.

telnet host.your.domain 25

220 host.your.domain ESMTP service (Netscape Messaging Server)
helo
250 host.your.domain
mail from: santa.claus@north.pole
250 Sender  Ok
rcpt to: postmaster@your.domain
250 Recipient  Ok
data
354 Ok Send data ending with .
hello ! this is a testmail !
.
250 Message received: G6LP5E00.600
quit
221 host.your.domain ESMTP server closing cennection


Author: Markus Bangerter / Last Update: 04.01.2001