Some email messages marked "Unverified" in Outlook
Since launching Azure Email Communication Services for our app, we have been seeing some transient issues with sender verification. Our send domain is validated in the Azure Portal with everything green.
However, occasionally we will see emails received by Outlook in Microsoft 365 being marked as “Unverified”. We have removed old SPF records from the DNS so now it should only include the parts necessary for Azure Communication Services. I have also double checked the DKIM/CNAME records.
I have attached email information from Outlook on the web where you can see the authentication failure.