Unable to parse Umlaute

[clicks]

Infos:

• Used Zammad version: 2.6
• Used Zammad installation source: https://dl.packager.io/srv/zammad/zammad/stable/installer/ubuntu/16.04.repo
• Operating system: Ubuntu 16.04.5 LTS
• Browser + version: n/a

Expected behavior:

• No errors in scheduler_out.log.

Actual behavior:

• scheduler_out.log

Steps to reproduce the behavior:

• scheduler_out.log shows several entries where it stumbles upon German Umlaute, e.g.:
  Mail::AddressList can not parse |“Martin Müstermann” martin.muestermann@example.com|
  Reason was: Only able to parse up to "Martin M

This seems to be new in 2.6

[MrGeneration]

Can you please provide the full header of the mail druncated?

[clicks]

Here is one (anonymized) example with Cyrillic letters, which could only be parsed to the first letter:

Received: from mail-qt1-f175.google.com (xxx.xxx.xxx.xxx) by
MX-HOST.ad.example.de (xxx.xxx.xxx.xxx) with Microsoft SMTP Server (TLS) id
14.3.408.0; Thu, 27 Sep 2018 09:23:35 +0200
Received: by mail-qt1-f176.google.com with SMTP id x23-v6so1725579qtr.1
for info@example.de; Thu, 27 Sep 2018 00:24:30 -0700 (PDT)
From: =?UTF-8?B?0JDQu9C10LrRgdC10Lkg0KHQtdC80LXQvdC+0LI=?=
johndoe@gmail.com
Date: Thu, 27 Sep 2018 10:24:17 +0300
Message-ID: CABnGC-jOZ7X6TCLvHdZJep4uSR=XziB-tgMWe-KjO1dB5VFH+A@mail.gmail.com
Subject: Delivery to Russia
To: info@example.de
Content-Type: text/plain; charset=“UTF-8”
X-WatchGuard-Spam-ID: str=0001.0A0B0201.5BAC85AE.007C,ss=1,re=0.000,recu=0.000,reip=0.000,cl=1,cld=1,fgs=0
X-WatchGuard-Spam-Score: 0, clean; 0, virus threat unknown
X-WatchGuard-Mail-Client-IP: xxx.xxx.xxx.xxx
X-WatchGuard-Mail-From: johndoe@gmail.com
X-WatchGuard-AntiVirus: part scanned. clean action=allow
Return-Path: johndoe@gmail.com
X-MS-Exchange-Organization-AuthSource: MX-HOST.ad.example.de
X-MS-Exchange-Organization-AuthAs: Anonymous
X-TM-AS-Product-Ver: SMEX-11.1.0.1278-8.200.1013-24120.003
X-TM-AS-Result: No–1.072900-4.000000-31
X-TM-AS-User-Approved-Sender: No
X-TM-AS-User-Blocked-Sender: No
X-MS-Exchange-Organization-AVStamp-Mailbox: SMEX|\xt;1452900;0;This mail has
been scanned by Trend Micro Messaging Security Agent;
X-MS-Exchange-Organization-SCL: 0
MIME-Version: 1.0