I have just bought a win 8.1 laptop and installed Thunderbird to talk to my IMAP server. The problem is that Thunderbird dont show any unread messages. If i connect to my server from another program, like the mail program on my android phone, I can see all unread mail. Opening an unread mail on my phone will make it appear instantly in my Thunderbird inbox.

Any help to solve this mystery will be greatly appreciated.