Can't get Davdroid + posteo working on Open OS 17.06.4

I can’t get Davdroid (F-Droid) running. It will accept my account at, ask me to accept the certificate but then gives an error. 'Couldn’t find CalDAV or CardDAV service.'
I find this very strange, because before the update to Open Android 6 it was working perfect.

grrr I tried to export my contacts through the webpage of But the vcf.file import fails.
and my backup in oandbackup fails also.


Hope it helps…

1 Like

Posteo seems to run on port 8843 (before: 8443) now. Did you try that? We have updated


Thank you so much. This solved my problem.