Delayed email delivery to Microsoft 365 – 15 October

We experienced delays with delivering outgoing email email from our Dallas server WWW-29 to domains hosted on Microsoft 365.

16:20 GMT Original report
Email from our Dallas server WWW-29 is currently unable to deliver. Microsoft has placed a greylisting restraint on the main server IP address due to a supposed “change in the email patterns”. We have reached out to Microsoft to have the limits removed.

17:20 Update
We are still awaiting response to our support ticket with Microsoft. In the meantime, we are mitigating the problem by using a secondary IP address (that is not greylisted) for outgoing email. All services are normal at this time.