Some email clients change the subject of the email to  `...`
when trying to protect the mail headers, by this technical-idea

  https://github.com/autocrypt/memoryhole/

Overall I do not think that memoryhole is a bad idea
as the envelope of paper mails is also unencrypted 
and the trace the envelope leaves behind is something that user
need to be aware of. If also reduces the usability of email in many
cases because of the long transition period.

== Topic chanced to ...
If in a fully encrypted setup, an answer to an email is send to
roundup with ... as subject it will change it to this subject.

== Technical consideration
The first step could be to not chance a subject if one of the memoryhole detecting header is set.

Okay paste and change mistake

I do think that 
  memoryhole is a bad idea!

On Fri, Oct 02, 2020 at 08:08:20AM +0000, Bernhard Reiter wrote:
> 
> == Technical consideration
> The first step could be to not chance a subject if one of the
> memoryhole detecting header is set.

This can already be done by setting

subject_updates_title = no
in the [mailgw] section of config.ini

This, of course, prevents *all* title updates via the subject. I've
generally found that turning this off in production trackers is a good
idea with all the subject mangling going on with diverse mail clients.

You can still set the title explicitly via email by appending
[title=new title] to the subject :-)

Ralf
-- 
Dr. Ralf Schlatterbeck                  Tel:   +43/2243/26465-16
Open Source Consulting                  www:   www.runtux.com
Reichergasse 131, A-3411 Weidling       email: office@runtux.com

Ralf,
thanks, good hint. :)