Here is part of a log file from /var/spool/mail...I'm not sure if its the right one. I don't really understand how the mail works...how does it get the sender email address? When I receive the messages it shows that the sender is simply Chen <Allen>
Return-Path: <MAILER-DAEMON>
Received: from localhost (localhost)
by allen (8.13.1/8.13.1) id m92C7bG4001886;
Thu, 2 Oct 2008 08:07:37 -0400
Date: Thu, 2 Oct 2008 08:07:37 -0400
From: Mail Delivery Subsystem <MAILER-DAEMON>
Message-Id: <200810021207.m92C7bG4001886@allen>
To: <root@allen>
MIME-Version: 1.0
Content-Type: multipart/report; report-type=delivery-status;
boundary="m92C7bG4001886.1222949257/allen"
Subject: Warning: could not send message for past 4 hours
Auto-Submitted: auto-generated (warning-timeout)
This is a MIME-encapsulated message
--m92C7bG4001886.1222949257/allen
**********************************************
** THIS IS A WARNING MESSAGE ONLY **
** YOU DO NOT NEED TO RESEND YOUR MESSAGE **
**********************************************
The original message was received at Thu, 2 Oct 2008 04:03:03 -0400
from localhost.localdomain [127.0.0.1]
----- Transcript of session follows -----
451 allen: Name server timeout
451 allen: Name server timeout
451 allen: Name server timeout
Warning: message still undelivered after 4 hours
Will keep trying until message is 5 days old
451 allen: Name server timeout
--m92C7bG4001886.1222949257/allen
Content-Type: message/delivery-status
Reporting-MTA: dns; allen
Arrival-Date: Thu, 2 Oct 2008 04:03:03 -0400
Final-Recipient: RFC822; root@allen
Action: delayed
Status: 4.4.3
Last-Attempt-Date: Thu, 2 Oct 2008 08:07:37 -0400
Will-Retry-Until: Tue, 7 Oct 2008 04:03:03 -0400