E-Mail with ics object as attachment

[passt]

Hi everybody.
(zarafa 7.2.6.10-3.1)
When I receive an e-mail with an ics attachment, Zarafa webapp shows it as an appointment object in the inbox. The result is that the body of the e-mail is shown in ureadable plain text instead of html. This is annoying for instance for e-mails sent as reservation confirmations by booking portals.
Even more worse those appointment objects aren’t shown on mail clients which are connected via activesync with zarafa, e.g. Outlook 2016 or android mail client.

Does anybody have a clue what to do?

regards,
Peter