What Are E-mail Headers?
E-mail headers are the structured fields part of an e-mail message such as From, To, CC, Subject, Date, and other information about the email. They will also include any bounce or return messages that will help technical support staff in troubleshooting if e-mail won't go through. See an example of e-mail headers below. This example is longer and more complex than most, but it is meant to give you an idea of the information you should be looking for.
From: MAILER-DAEMON@MAILER-DAEMON [mailto:MAILER-DAEMON@MAILER-DAEMON]
Sent: Friday, June 29, 2010 7:33 AM
To: John Doe
Subject: Undeliverable: Monthly Status Draft Delivery has failed to these recipients or distribution lists:
An error occurred while trying to deliver this message to the recipient's e-mail address. Microsoft Exchange will not try to redeliver this message for you. Please try resending this message, or provide the following diagnostic text to your system administrator.
The following organization rejected your message: another-domain.com.
Diagnostic information for administrators:
Generating server: bigfish.com
#SMTP# Original message headers:
Received: from mail187-tx2-R.bigfish.com (10.9.14.242) by TX2EHSOBE003.bigfish.com (10.9.40.23) with Microsoft SMTP Server id 188.8.131.52; Fri, 29 Jun 2010 14:31:11 +0000
Received: from mail187-tx2 (localhost [127.0.0.1]) by mail187-tx2-R.bigfish.com (Postfix) with ESMTP id 65DA76020F for ; Fri, 29 Jun 2010 14:31:11 +0000 (UTC)
Received-SPF: pass (mail187-tx2: domain of some-domain.com designates 184.108.40.206 as permitted sender) client-ip=220.127.116.11; email@example.com; helo=MDTSSWEEDGOUT02.mail.some-domain.com ;.mail.some-domain.com ;
Received: from mail187-tx2 (localhost.localdomain [127.0.0.1]) by mail187-tx2 (MessageSwitch) id 1340980268877525_3932; Fri, 29 Jun 2010 14:31:08 +0000 (UTC)
Received: from TX2EHSMHS015.bigfish.com (unknown [10.9.14.241]) by mail187-tx2.bigfish.com (Postfix) with ESMTP id D218E32004A for ; Fri, 29 Jun 2010 14:31:08 +0000 (UTC)
Received: from MDTSSWEEDGOUT02.mail.some-domain.com (18.104.22.168) by TX2EHSMHS015.bigfish.com (10.9.99.115) with Microsoft SMTP Server (TLS) id 22.214.171.124; Fri, 29 Jun 2010 14:31:06 +0000
Received: from MDTSSWEHT07.rf01.some-domain.com (126.96.36.199) by MDTSSWEEDGOUT02.mail.some-domain.com (188.8.131.52) with Microsoft SMTP Server (TLS) id 8.3.264.0; Fri, 29 Jun 2010 07:32:14 -0700
Received: from MDTSSWECH14.rf01.some-domain.com (184.108.40.206) by MDTSSWEHT07.rf01.some-domain.com (220.127.116.11) with Microsoft SMTP Server (TLS) id 8.3.264.0; Fri, 29 Jun 2010 07:32:23 -0700
Received: from MDTSSWECCR19.rf01.some-domain.com ([169.254.1.91]) by MDTSSWECH14.rf01.some-domain.com ([18.104.22.168]) with mapi; Fri, 29 Jun 2010 07:32:23 -0700
From: "John Doe"
To: 'Jane Doe'
Date: Fri, 29 Jun 2010 07:32:22 -0700
Subject: Monthly Status Draft
Thread-Topic: Monthly Status Draft