Redmine

Hi,

my Installation on a CentOS 7 Servere:

Environment:
Redmine version 4.0.4.stable
Ruby version 2.6.2-p47 (2019-03-13) [x86_64-linux]
Rails version 5.2.3
Environment production
Database adapter Mysql2
Mailer queue ActiveJob::QueueAdapters::AsyncAdapter
Mailer delivery smtp
SCM:
Git 1.8.3.1
Filesystem
Redmine plugins:
redmine_checklists 3.1.16
redmine_ckeditor 1.2.2

When I send the following Mail to redmine:

This is a test
--

Mit freundlichen Grüßen / With best regards
i.V. Ing. Gerhard Kronstorfer
Abteilungsleiter EDV

I get the following ticket (created by rdm-mailhandler):

This is a multi-part message in MIME format.
--------------5CDD95DC82FDEC6C69D3183F
Content-Type: text/plain; charset=utf-8; format=flowed
Content-Transfer-Encoding: 8bit

This is a test
--

Mit freundlichen Gr????en / With best regards
i.V. Ing. Gerhard Kronstorfer
Abteilungsleiter EDV

You can see that there are four additional lines at the start of the ticket which shouldn't be there and that there is a problem with the special characters in the signature.

If I send the same message to my old Installation (redmine 3 on Centos 6) everything ist fine.

Any idea how can I solve this two Problems?