machine$ telnet my_mail_server.com 25
Trying 172.18.29.85
Connected to my_mail_server.com.
Escape character is '^]'.
220 my_mail_server.com ESMTP ReegenMail
helo my_test_server.com
250 my_mail_server.com Hello my_test_server.com [192.168.98.91], I'm
listening
mail from: <test@My_test_server.com>
250 test@my_test_server.com... Sender ok
rcpt to: <testuser@my_mail_server.com>
250 testuser@my_mail_server.com... Recipient ok
data
354 enter mail, end with '.' on a line by itself
TO: testuser@my_mail_server.com
FROM: test@my_test_server.com
Subject: This is a test

This is a test of the messaging system
.
250 011264701 Message accepted for delivery
quit
221 my_mail_server.com closing connection