Two folders in your mailbox have the same name.

Two folders with the name Notes have been found in your mailbox. Please connect to your mailbox using your Web browser and rename one of the folders. After you rename one folder, your IMAP e-mail application will be able to display both folders.

Ich habe schon nachgeschaut.. Nein, ich habe keine zwei Ordner mit denselben Namen, habe keinen Ordner eigentlich.