Hello there,
I recently change my SSL certs. of my webserver. Since this happening I'm no longer able to load new incoming Mails in Programs like Thunderbird, Outlook and co. Online there is no problem to get the mails through web application. Is this a common problem?
Thx for any help!
You should have a look at the authorization logs on the server to see how the authentication attempts are failing.
If I had to guess, I'd say your previous configuration was using the same certs for the web server and the mail server (MTA). If you deleted the old certs when you changed them for the web server, that would leave the MTA misconfigured to point at certs that are no longer there.
If that's the case, it means Roundcube works because the MTA doesn't require local sessions to authenticate, whereas your remote clients are required to authenticate and can't because of the cert problem.
That's my best guess on limited information. Is this a Linux server or a Windows server? Do you know what MTA is running?