There is currently a significant mail backlog on cloudp.spamtitan.com, starting before 7:00 ET US. Currently cloudp.spamtitan.com is working through its backlog quickly. Also, we have closed inbound port 25 on that SpamTitan so it can focus on its backlog, while the other two SpamTitan (cloudq.spamtitan.com and cloudr.spamtitan.com) are processing mail normally and keeping up with the current inbound.
10:30 AM ET US
We will be providing another update in about 30 minutes.
11:15 AM ET US
The queue are clear on all three nodes.
We apologize again for the inconvenience.