all mails become marked as "not read"

Hello,

A few days ago, suddenly, all the messages of my account “orange” become marked as “unread”.
The “Mark all messages as read” button works.
Then all messages become “unread” again.
Emclient or provider problem?
Another account is “unread”.

Thank you.

I would suspect the provider, but maybe another device that is connected to the same IMAP account.

If you are not using the latest version, you can download and install it from http://www.emclient.com/release-history and see if there is any difference.