Evolution header format

Subject: header test
From: Username <username@sendinghost.com>
To: Username <username@receivinghost.com>
Content-Type: text/plain
Date: Sat, 28 Jul 2007 11:52:35 +0200
Message-Id: <1185616355.19231.0.camel@localhost>
Mime-Version: 1.0
X-Mailer: Evolution 2.10.1
Content-Transfer-Encoding: 7bit

The Message id consists of five parts:

  1. The current time as returned by the time function followed by a period. The value is dislayed in decimal and is the number of seconds since midnight on 1 Jan 1970. In the example above, 1185616355 refers to Sat, 28 Jul 2007 09:52:35 GMT.
  2. The process id number in decimal followed by a period
  3. The third value starts at zero but may increase as more messages are sent. It is also followed by a period
  4. The word camel followed by an '@'
  5. If the canonical hostname can found, it is used. Otherwise the hostname

The Message id format comes from the function camel_header_msgid_generate in evolution-data-server/camel/camel-mime-utils.c.