Most of the time, thunderbird can connect to the server for my gmail account, and sending and receiving email via this account works fine Sometimes, however, I get a message 'Failed to connect to server imap.gmail.com', and no new emails can be send or received (two other non-gmail accounts work fine). Usually after a restart the synchronization works again. Is this a problem with server settings in thunderbird, or is the problem with Google? I've included a screenshot with the current server settings.