Microsoft 365 Alert – Service Degradation – Exchange Online – Some admins may be unable to migrate on-premises mailboxes to Exchange Online – RESOLVED

Announcements Sourav Nandi

26/07/2023 08:35:00 AM (GMT)

NHSmail Reference : INC37221462

Microsoft Reference : EX660399

Issue Status : RESOLVED

Issue Description : Some admins may be unable to migrate on-premises mailboxes to Exchange Online.

Current Update : 03/08/2023 10:22:00 AM – The fix has deployed successfully and Microsoft have confirmed that the issue is resolved after a period of monitoring.

Scope of impact : Some admins who are served through the affected infrastructure attempting to migrate on-premises mailboxes to Exchange Online may be impacted.

Root cause : A recent standard service update, contains a code regression that’s resulting in our Mailbox Replication Service (MRS) API calls, used to confirm the mailbox replication has completed, to return incorrect results and halt the migration completion.

Next steps : Microsoft are reviewing their service update procedures to prevent this problem from happening again.