Users report that they are unable to move and or delete items when using Outlook Web App. When they try to move or delete a message they get an unspecified error.
Open IIS manager, go to your default website, right click on it and select "Edit Bindings".
Check if any binding has a hostname configured. If one does, remove the hostname. You probably cannot remove the hostname, because the binding already exists. If so, remove the binding completly (where the hostname is specified). Restart IIS (IISRESET).