*** UPDATE *** 12:46 PM EST
Problem was affecting some customers in the US region. We have changed the routing of the outgoing email to bypass the problematic mail server, and currently working with provider to restore it, so all queued up email can be delivered.
*** UPDATE *** 1:38 PM EST
The problematic mail server connectivity has been restored. All messages that were queued up in that server are currently being delivered.
*** UPDATE *** 5:16 PM EST
Data center reports the problem was caused by a misconfiguration on one of their routers. They promise they will not do that again.
