Released: March 2024 Exchange Server Security Updates

I'm managing a site with around 250 users who have email addresses on our on-premise Exchange 2016 server.

No we DO NOT have Office 365

I installed this latest March Exchange patch over the weekend.   After installing this patch we are having problems with users who are attempting to add their email accounts to their mobile devices using the Outlook for Mobile client.   Users who already have Outlook for Mobile client setup on their phone with their account already added are fine, they are able to continue accessing their email.   It is the NEW users, and it is also users who have deleted their account then attempted to add it back in who are having problems.

I ran the https://testconnectivity.microsoft.com Remote Connectivity Analyzer and it shows no problems accessing our Exchange server.

Interestingly, on my Google Pixel 6a phone I can uninstall the Microsoft Outlook Mobile app, and reinstall it, and successfully connect it to a test Linux mailserver running Postfix and Dovecot, using IMAP, and it works perfectly.

I can also setup the Google-written and supplied Android email application to connect to our Exchange server using the Outlook connector Google wrote and it also works perfectly as well.

I would like to submit my 6 year old son for consideration of a job working for Microsoft in the Exchange development arena as clearly, his coding and testing skills are superior to any MS Exchange developers.  Actually, my dog probably has better coding skills.

The one thing I do want to thank you all for is we have been considering NOT buying a new Exchange server when this one EOL's and replacing it with a Linux mailserver.  Those plans have gotten a tremendous boost by this screwup.