telnet capone.linux.class 110
Trying 192.168.5.240...
Connected to 192.168.5.240.
Escape character is '^]'.
+OK
USER mailtest
+OK
PASS Password 
+OK
RETR 1
+OK
Return-Path: 
X-Original-To: mailtest@capone.linux.class
Delivered-To: mailtest@capone.linux.class
Received: from node18.linux.class (node18 [192.168.5.38])
        by capone.linux.class (Postfix) with ESMTP id A291B2B15C
        for ; Tue, 12 Apr 2005 22:24:53 -0400 (EDT)
Received: from here.com (unknown [192.168.5.250])
        by node18.linux.class (Postfix) with SMTP id 4653B14112
        for ; Tue, 12 Apr 2005 22:24:03 -0400 (EDT)
To: some_guru@somewhere.com
From: pp@pp.com
Subject: Forged e-mail
Message-Id: <20050413022403.4653B14112@node18.linux.class>
Date: Tue, 12 Apr 2005 22:24:03 -0400 (EDT)

Hey, 
The "To:" and "From:" are non-existent, but you still get the e-mail.
bye, bye
.
DELE 1
+OK
QUIT