"Character not allowed in mailbox name: '.' "

Hello,
as of today I get errors while eM Client is updating incoming mailboxes. I didn’t chance my configuration that was running successful for about a year now.

This is what comes up: Folder “norbert@xyxyxyxy.de/Shared/kalender.aundn@ xyxyxyxy.de/INBOX/” cannot be opened. ([CANNOT] Character not allowed in mailbox name: ‘.’) 

What’s going wrong suddenly? It’ll be great someone could help. 

Looks like eM Client does not like the . in the folder name.

Open the web interface for your account, and change the folder name.

The issue was caused by the mail hosting company. They apologized. Problem is solved.