On April 22nd 2021 around approx. 8am PST Microsoft Office 365 customers in North America began seeing elevated message queues. Area 1 customers are being protected during this event by the Area 1 Horizon service automatically holding any messages for redelivery that were being throttled by Microsoft’s service downstream. During this event, there was no loss of emails; and messages were automatically delivered once Microsoft’s issue has been resolved.
More information about the service delivery issue can be found on https://status.office365.com/
Should you have any questions, please contact Area 1 support for further information.