Some header fields like "Received" appear are more than one time in a mail header. So, a Hash is not a good idea to put in the header fields. This results in missing "Received" fields, because the key is unique.
Example:
E-Mail
Return-Path: <newsletter@basislager.de>
X-Original-To: aaron@gridbag.net
Delivered-To: aaron@gridbag.net
Received: by remote.gridbag.net (Postfix, from userid 5001)
id 1A4894E0698; Fri, 2 Oct 2015 16:46:50 +0200 (CEST)
X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on
lvps83-169-3-141.dedicated.hosteurope.de
X-Spam-Level:
X-Spam-Status: No, score=-0.7 required=6.0 tests=RCVD_IN_DNSWL_LOW,
URIBL_BLOCKED autolearn=unavailable version=3.3.1
Received: from vwp11863.webpack.hosteurope.de (vwp11863.webpack.hosteurope.de [91.250.70.227])
(using TLSv1 with cipher AES256-SHA (256/256 bits))
(No client certificate requested)
by remote.gridbag.net (Postfix) with ESMTPS id D676F4E0613
for <mail@aaron-mueller.de>; Fri, 2 Oct 2015 16:46:49 +0200 (CEST)
Received: from pd95c6860.dip0.t-ipconnect.de ([217.92.104.96] helo=[192.168.20.12]); authenticated
by vwp11863.webpack.hosteurope.de running ExIM with esmtpsa (TLS1.0:DHE_RSA_AES_128_CBC_SHA1:16)
id 1Zi1bi-0006zp-VF; Fri, 02 Oct 2015 16:46:47 +0200
Some header fields like "Received" appear are more than one time in a mail header. So, a Hash is not a good idea to put in the header fields. This results in missing "Received" fields, because the key is unique.
Example:
E-Mail
Parser result: