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.