Gmail Header Format - Revision history

Jessek: /* Message Id Field */ - repeated word

2009-01-05T03:15:43Z

‎Message Id Field: - repeated word

Jessek: Added See Also Section

2007-10-24T01:10:20Z

Added See Also Section

Jessek: Added more detail on message id verification

2007-10-24T01:09:01Z

Added more detail on message id verification

Jessek: Added timestamp in message ID

2007-10-23T12:15:49Z

Added timestamp in message ID

Jessek: Added DKIM Link

2007-04-29T18:14:00Z

Added DKIM Link

Jessek at 05:16, 6 March 2007

2007-03-06T05:16:57Z

Jessek at 05:14, 6 March 2007

2007-03-06T05:14:08Z

Jessek: Initial Stub

2007-03-06T05:13:33Z

Initial Stub

New page

Because [[Gmail]] is a [[web based application]] and can be changed at any time, the information in this article may not reflect the current state of Gmail headers. In general Gmail headers have a DKIM signature line that contains a signature for the message in question. These lines appear above the standard Message-ID fields. These signatures are of the format:

<pre>DKIM-Signature: a=rsa-sha1; c=relaxed/relaxed;
d=gmail.com; s=beta; h=domainkey-signature:received:received:message-id:date:from:to:subject:mime-version:content-type; b=OITvzFGKQQUjywUQB7U8dQypDAeOGqBIhfcb8VKioP2UU5P2aJL3l2adoyRqSp9h/Fo9A6wY5EIRsfaCWM9ge+EzCob/4p85jcEn3uW8dpRyBFQXMuK2q0RMIk3FznrXAM4W5FvoJIPP04qgXErar+/hZq03vEUIErV1v6p2Fy4=
DomainKey-Signature: a=rsa-sha1; c=nofws;
d=gmail.com; s=beta;
h=received:message-id:date:from:to:subject:mime-version:content-type; b=oC+hlWhBboQ+RlsKCL4r2pQxpgKRM9iUgCBmw9wZqlEcxj+A3q+fJkDXgLKmI1twfvTHj7GQ3HDzSLzw982UD+CPh1bPQxkhNbylUBRtwpoFeixIk7OmR2YE1iYrYpQXf3dEcXNfKs7ffoeY18plJNJG0S8RRmXLaR6XqXFVUoo=
</pre>

Note that some of the <tt>Received</tt> lines will contain hosts with IP addresses like 10.x.x.x. These addresses are non-routable but part of the Gmail system. The remaining headers look like:

<pre>Message-ID: <f6a363400703050910y7d591d42raf015fcef16f95ea@mail.gmail.com>
Date: Mon, 5 Mar 2007 09:10:41 -0800
From: UserName <address@gmail.com>
To: OtherUserName <address@system.com>
Subject: Subject Line
MIME-Version: 1.0</pre>

The format of the Message-ID field is not known.

== External Links ==
* [https://mail.google.com/ Gmail]
* [http://www.elandsys.com/resources/sendmail/dkim.html DKIM Signatures]

@@ Line 24: / Line 24: @@
 == Message Id Field ==
-Although the message id format is not completely understood, it contains the date and time the message was sent, in pacific time, starting at the ninth digit, in the form YYMMDDHHMM. In the example above, the time/date is <tt>0703050910</tt>, 0910 PDT on 5 Mar 2007. This has been confirmed by experimental testing. If you are trying [[Using signature headers to determine if an email has been forged|trying to determine if a message has been forged]], you should verify that the time in the Message Id field matches the time in the Date field for the message. Don't forget that the time in the Date field should be in the Sender's local time and the Message Id will be in Google's local time, US Pacific Time.
+Although the message id format is not completely understood, it contains the date and time the message was sent, in pacific time, starting at the ninth digit, in the form YYMMDDHHMM. In the example above, the time/date is <tt>0703050910</tt>, 0910 PDT on 5 Mar 2007. This has been confirmed by experimental testing. If you are [[Using signature headers to determine if an email has been forged|trying to determine if a message has been forged]], you should verify that the time in the Message Id field matches the time in the Date field for the message. Don't forget that the time in the Date field should be in the Sender's local time and the Message Id will be in Google's local time, US Pacific Time.
 == See Also ==

← Older revision		Revision as of 18:14, 29 April 2007
Line 1:		Line 1:
−	Because [[Gmail]] is a [[web based application]] and can be changed at any time, the information in this article may not reflect the current state of Gmail headers. In general Gmail headers have a ~~DomainKey~~ Identified Mail (DKIM) signature line that contains a signature for the message in question. These lines appear above the standard Message-ID fields. These signatures are of the format:	+	Because [[Gmail]] is a [[web based application]] and can be changed at any time, the information in this article may not reflect the current state of Gmail headers. In general Gmail headers have a [[DomainKeys Identified Mail]] (DKIM) signature line that contains a signature for the message in question. These lines appear above the standard Message-ID fields. These signatures are of the format:

	<pre>DKIM-Signature: a=rsa-sha1; c=relaxed/relaxed;		<pre>DKIM-Signature: a=rsa-sha1; c=relaxed/relaxed;

← Older revision		Revision as of 05:14, 6 March 2007
Line 1:		Line 1:
−	Because [[Gmail]] is a [[web based application]] and can be changed at any time, the information in this article may not reflect the current state of Gmail headers. In general Gmail headers have a DKIM signature line that contains a signature for the message in question. These lines appear above the standard Message-ID fields. These signatures are of the format:	+	Because [[Gmail]] is a [[web based application]] and can be changed at any time, the information in this article may not reflect the current state of Gmail headers. In general Gmail headers have a DomainKey Identified Mail (DKIM) signature line that contains a signature for the message in question. These lines appear above the standard Message-ID fields. These signatures are of the format:

	<pre>DKIM-Signature: a=rsa-sha1; c=relaxed/relaxed;		<pre>DKIM-Signature: a=rsa-sha1; c=relaxed/relaxed;

@@ Line 25: / Line 25: @@
 Although the message id format is not completely understood, it contains the date and time the message was sent, in pacific time, starting at the ninth digit, in the form YYMMDDHHMM. In the example above, the time/date is <tt>0703050910</tt>, 0910 PDT on 5 Mar 2007. This has been confirmed by experimental testing. If you are trying [[Using signature headers to determine if an email has been forged|trying to determine if a message has been forged]], you should verify that the time in the Message Id field matches the time in the Date field for the message. Don't forget that the time in the Date field should be in the Sender's local time and the Message Id will be in Google's local time, US Pacific Time.
 == External Links ==
 * [https://mail.google.com/ Gmail]
 * [http://www.elandsys.com/resources/sendmail/dkim.html DKIM Signatures]

@@ Line 2: / Line 2: @@
 <pre>DKIM-Signature: a=rsa-sha1; c=relaxed/relaxed;
-         d=gmail.com; s=beta;        h=domainkey-signature:received:received:message-id:date:from:to:subject:mime-version:content-type;        b=OITvzFGKQQUjywUQB7U8dQypDAeOGqBIhfcb8VKioP2UU5P2aJL3l2adoyRqSp9h/Fo9A6wY5EIRsfaCWM9ge+EzCob/4p85jcEn3uW8dpRyBFQXMuK2q0RMIk3FznrXAM4W5FvoJIPP04qgXErar+/hZq03vEUIErV1v6p2Fy4=
+         d=gmail.com; s=beta;
 DomainKey-Signature: a=rsa-sha1; c=nofws;
          d=gmail.com; s=beta;
-         h=received:message-id:date:from:to:subject:mime-version:content-type;        b=oC+hlWhBboQ+RlsKCL4r2pQxpgKRM9iUgCBmw9wZqlEcxj+A3q+fJkDXgLKmI1twfvTHj7GQ3HDzSLzw982UD+CPh1bPQxkhNbylUBRtwpoFeixIk7OmR2YE1iYrYpQXf3dEcXNfKs7ffoeY18plJNJG0S8RRmXLaR6XqXFVUoo=
+         h=received:message-id:date:from:to:subject:mime-version:content-type;
 </pre>