January 1, 2022 12:00pm – Happy New Year! The new year brings more of the same old problems. In this case, a bug in the anti-malware engine of Microsoft Exchange servers has caused email delivery to stop. Customers who have their own on premise Exchange server will be affected by this. There is no official patch just yet. The bug is in the anti-malware service on these servers and the current work around is to stop this service. You can find an article with more information about this bug here.
Email delivery will be delayed and senders who send to people using these Exchange servers may/will receive a “delayed delivery notification”. As long as the issue has been addressed within a few days, those emails will eventually be delivered. If any sender has a short retry time setup on their email, they will receive a second “failure notice” indicating that the email did not go through and will not be tried any longer. The industry standard is for email delivery to be retried 5 days, but this can be adjusted by individual email operators.
If you have any questions or concerns, please email us at email@example.com. Please keep in mind that our office is closed for the holiday, so you may not receive an immediate response. We are working on implementing the workaround for customers with proactive support contracts and those who report the issue to us and wish it fixed at holiday/after hours rates. This will allow the email to be delivered. For others, we will be rolling out the workaround or fix if it has been rolled out during normal business hours Monday.
Update – Microsoft has released an emergency fix which does require manual application. We are working to put this fix in place at normal rates for affected customers.