S/MIME Verification failed

ichi123

Hello everybody,

Currently I have a problem with the web / desk app from Kopano.
We use the S / MIME module to sign our emails.
It worked for a while.

Now the mails, which are sent via the Web- / Deskapp, arrive with “invalid signature”.

Mails, which are sent via Android (also signed), arrive with “valid signature”.

A look in the mail.log seems to give an indication of the problem:

via Android:
Feb 13 13:59:02 server amavis [20237]: (20237-05) Passed CLEAN {RelayedOutbound},

via Web- / Deskapp:
Feb 13 13:31:25 server amavis [20237]: (20237-04) Passed BAD-HEADER-8 {RelayedOutbound, Quarantined},

Can someone help me in this regard?
What information is needed?

Thanks you for your help.

Update:
The mail in the format TEXT also works and the mail arrives with a valid signature.

Here are the version:
WebApp: 3.4.22.1782+80.1
Kopano Core: 8.6.8.2
SMIME Plugin: 1.0

Based on a Univention Corporate Server 4.3-3 errata428.