Update 11/13/2023: We added new information on how to know when this change is released to your organization.
Today, we are announcing an update to our requirements for SMTP relay through Exchange ...
Updated Feb 22, 2024
Version 19.0
Blog Post
To backup what others have said, we need to know when this gets changed in our tenants. If there's any reported issue with email relaying from now until early Q1 2024 (and that could mean until February?) how are we to know if it's related to this change or not? How will Microsoft support know if we raise a call related to a relay error?
I think it's a basic requirement to inform people when a change to their tenant is made, and Microsoft has been poor at doing this on a number of changes like this.
To be clear this criticism isn't aimed at Carolyn_Liu, who I think has been excellent in this blog, but I think it needs to be fed back to whoever plans and managers these changes.