Kopano, Z-Push, iPhone (ssl-problem)




i’m trying to connect an iphone (ios 12.3) to kopano. Android works. I only have the possibility to switch ssl on or off in the account settings of the iphone. However, the connection is denied because the certificate is not trusted. How do I transfer the certificate from the UCS (here kopano is running) to the iPhone for the connection to work?

with best sven


Hello Pixel,
do you use the UCS self-signed certificate or did you install Letsencrypt. With a vilid Letxencrypt certificate it should work.

Using self-signed cetificate on IOS 10 and above is a little bit tricky.
One quick and dirty method is downloading the root certificate and the SSL certificate onto the iPhone. After that go to Settings - General - Info/About - Certificate Trust Settings, and there is a section called
Under it lists the certificate(s), you installed previously on your iPhone. Enable them.

After this corcedure you should be able to setup the Kopano account on your iPhone.

I use this method on our company-Exchange Server since 6 years and it worked all the time on alle Apple devices as long as te certificates are not outdated.

It is a poor way to use and so I will switch to Letsencrypt next.

I recommend, first to install and configure Letsencrypt with your Kopano and connect to your Kopano account then.



Yes, I also use self-signed certificates. I can find the root certificate in the UMC -> Login -> Menu -> Certificates but where can I find the second certificate?


Login into Univention Management
Goto system - Univention Registry
Type in “kopano” as search item scroll down the result list and find the location:


You will need the ssl_certificate_file.

I hope, it works for you. If not, I recommend to install Letsencrypt. With the signed certificates you should have bo trouble.