9:15 AM Pacific —  Our monitoring has detected some minor replication issues, related to the changes made on Wednesday.  As a result, some new mailboxes added late last evening or early morning local time have not been fully replicated to all of the database slaves.

This is being rectified now and should be resolved within the next 15-30 minutes.

The engineering team has also identified the source of this replication error and it should not recur.

We apologize for the inconvenience.