[Evolution] Some HTML-emails not rendering correctly

[Trond Husø <trond trondhuso no>]

I am receiving some HTML-e-mails not being presented/rendered
correctly.
When I check the complete headers in Evolution I am getting only one
line.
When I open up the same message in SquirrelMail I see the below
information when checking the header (Some information removed for
privacy reasons). (my e-mail address-domain is changed to example.com,
sender changed to sender.com and the remote IP is changed to x.x.x.x)

The message just contains base64 "scramble". 

Running Ubuntu 16.04.

Evolution version is 3.18.5.2

Looking forward to figguring this out.

Best regards,

Trond


Return-Path: <newsletter sender com>
X-Original-To: iadb@example example com
Delivered-To: iadb@example example com
Received: from localhost (localhost [127.0.0.1])
     by server1 example example com (Postfix) with ESMTP id 1318F810A2
     for <example example com>; Fri, 6 Jan 2017 14:08:26 +0100 (CET)
X-Virus-Scanned: Debian amavisd-new at server1 example example com
Received: from server1 example example com ([127.0.0.1])
     by localhost (server1 example example com [127.0.0.1]) (amavisd-
new, port 10024)
     with ESMTP id 16th8d6QLFre for <example example com>;
     Fri, 6 Jan 2017 14:08:21 +0100 (CET)
Received: from server.sender.com (server.sender.com [x.x.x.x])
     by server1 example example com (Postfix) with ESMTP id E49758109A
     for <example example com>; Fri, 6 Jan 2017 14:08:20 +0100 (CET)
Received: by server.sender.com (Postfix, from userid 33)
     id ED9561982746; Fri, 6 Jan 2017 14:08:18 +0100 (CET)
To: Foo =?utf-8?Q?Hus=C3=B8?= <example example com>
Subject: NEWSLETTER JANUAR 2017
X-PHP-Originating-Script: 33:SimpleMailInvoker.php
Message-ID: <dae066519a8421b1e6745a13fae82b48 sender com>
Date: Fri, 06 Jan 2017 14:08:18 +0100
From: Sender.Com  <newsletter sender com>
Reply-To: Sender.Com <newsletter sender com>
MIME-Version: 1.0
Content-Type: multipart/alternative;
     boundary="_=_swift_v4_1483708098_49f8e62afbd7aefa3ae883c278ac69a4_
=_"
Organization: The Sender Dot Com
X-Priority: 3 (Normal)
X-TYPO3MID: MID498_t919-8a2604980c2af7176caf9a9b1b492143
X-Mailer: TYPO3