Microsoft 365 Alert – Service Degradation – Exchange Online – Some users’ incoming email messages are being quarantined unexpectedly in Exchange Online – RESOLVED

27/09/2023 09:01:00 AM (GMT)

NHSMail Reference: INC38523830

Microsoft Reference : EX677479

Issue Status : RESOLVED

Issue Description : Users’ incoming email messages are being quarantined unexpectedly in Exchange Online.

Final Update : 27/09/2023 09:01:00 AM – Following Microsoft’s review of system telemetry, as well as header logs of sample messages, they have assessed that a Domain Name System (DNS) configuration issue resulted in impact. They have corrected the DNS configuration and confirmed through telemetry that impact has been remediated.

Scope of impact : Your organization was impacted, and some users” incoming email messages were being quarantined unexpectedly in Exchange Online.

Root cause : A DNS configuration issue resulted in impact.

Next steps :  Microsoft will continue to review the context surrounding the offending DNS configuration change to help them better understand the source of the problem and prevent similar impact in the future.