An example mail transfer.
[burt@lee tmp]$ telnet localhost 25
Trying 127.0.0.1...
Connected to localhost.localdomain (127.0.0.1).
Escape character is '^]'.
220 lee.cs.miami.edu ESMTP Sendmail 8.13.1/8.13.1; Tue, 19 Apr 2005 14:47:48 -0400
HELO lee.cs.miami.edu
250 lee.cs.miami.edu Hello lee [127.0.0.1], pleased to meet you
MAIL FROM:<burt@disney.orgi>
250 2.1.0 <burt@disney.org>... Sender ok
RCPT TO:<burt@cs.miami.edu>
250 2.1.5 <burt@cs.miami.edu>... Recipient ok
DATA
354 Enter mail, end with "." on a line by itself
From: burt@nowhere.org
To: burt@cs.miami.edu
Subject: nice day
Hi
.
250 2.0.0 j3JIlmAn011598 Message accepted for delivery
QUIT
221 2.0.0 lee.cs.miami.edu closing connection
Connection closed by foreign host.
[burt@lee tmp]$