Decrypted mail blank in mail client

Dear All,

For SOHO purposes, I have been using a chiphermail gateway for a long time, traditionally in front of an Exchange server. Recently, I did swich to Kopano - please feel free to guess why.

There was one problem with decytped mails that annoyed me with Exchange but that is more critical with Kopano and I am unable to describe it adequately to Kopano. It might have to do with opaque signing or it might have other reasons.

When I receive an SMIME-encrypted e-mail, the gateway does decrypt it. With Exchchange, the behavior was:
- decrypted message was fully visible in outlook - one could work with it just as expected
- on Android (LineageOS, standard mail client), the decrypted message was marked as encrypted and not presentable despite the fact that it was in fact decrypted.
I found that annoying, but I could stand that. If needed, I did use OWA.

With Kopano, the behavior is:
- decrypted message is shown blank in Kopano client. When downloading in .eml format, it can be viewed (with Outlook, for example)
- on Android, the decrypted message is also shown blank. Just an smime.p7m enclosure is visible.

I would very much welcome, if Martijn or someone else could point me to the right direction to resolve this issue. Any help in describing the issue to Kopano and/or in understanding which features might have to be enabled in php and/or apache in use would be great.

Thanks & Regards,



Technische Universität Dresden
Fakultät Wirtschaftswissenschaften
Lehrstuhl für Entrepreneurship und Innovation
Prof. Dr. Michael Schefczyk
D-01062 Dresden

Fon: +49-3 51-4 63-3 68 81
Fax: +49-3 51-4 63-3 68 83