S/MIME signed mails showing unsigned

Hi,

I am using SMIME Plugin 2.2.0.167.
When sending signed messages in desktop- or webapp the message is correctly shown as signed in sent folder, but is shown unsignd in the inbox of the recipient. Same when sending signed messages to myself. In Outlook with ActiveSync without problems.

Encryption/Decryption works perfect in webapp!

Any idea?

Many thanks in advance!

Is the s/mime plugin enabled at the recipient side?

Problem is still not solved, but got new knowledge!
I am using exim as local MTA. When using exim all S/MIME signed mails are showing unsigned to the recipent. S/MIME headers are included but not recognized by the client. When using postfix instead of exim, S/MIME mail is correctly shown as signed.

So anybody here who has experiences with Kopano, S/MIME signing and exim as local MTA. Can anybody reproduce this? I would like to keep exim as mailer.

Many thanks in advance!

Workaround:
I am using now postfix as local MTA passing through to local exim. Now signed messages are correctly shown to the recipient when sending from Web- or DesktopApp. Issue was handed over to Kopano Support.