July 20, 2022 – We have received some reports of users using Office 365 (Microsoft 365) services having trouble emailing our users. The bounce back messages or non-delivery reports are stating that the issue is on the Microsoft side due to misconfigured PTR records. A PTR record is similar to caller ID for computers. It allows one to look up the IP address and get a host name back. Best practices state that this should be present for email delivery and in specific formats. Here is an article about this for those of you who would like more information on it: https://www.linuxmagic.com/best_practices/valid_ptr.html
It seems that Microsoft has made a change and is not following these practices at the moment. We are looking into whether this is something that has been done by mistake and will be corrected or if they have done it on purpose for some reason. We are currently very strict on PTR record validity because it does help us prevent spam. Not all ISPs and email operators are as strict, so the Office 365 emails will go through to some addresses. We will be posting updates on this as we have them.
Update 12:00pm – We have confirmed with our email vendor that this is a Microsoft issue that has been going on about 12 hours. It is being discussed by the major email providers but Microsoft has not released a statement as yet, so there is not currently an estimated time to repair.
Update July 22 11:00am – We have not seen any statement from Microsoft on this, but have also not been seeing the issues continuing, so we do believe that Microsoft has corrected this on their end. If you are still seeing the problem, please let us know by calling 256-547-6817 or emailing firstname.lastname@example.org.