The Ghost server will be migrated this week. The exact time cannot be stated due to the size of the data and the dynamics around keeping it synchronized between two servers. Expect that you may delete emails or move them to another folder, only to see them reappear later. This should occur once. You may also have briefly interrupted POP/IMAP connectivity during the transition, resolving itself nearly instantly for 99% of users (and at most an hour for anyone else). Inbound and outbound email will not be impacted by this event.