Microsoft is currently monitoring the issue (IssueID: EX1052569). After Microsoft disabled recently deployed changes yesterday evening, no further issues have occurred. We are therefore closing this incident.

We are slowly seeing an improvement at MS Graph. It seems that Microsoft has fixed the error. An official confirmation from Microsoft is still pending. Due to the large volume of accumulated mails, the processing of the data may take some time. (Microsoft Issue ID: EX1052569)

Microsoft has identified that impact is specific Mailboxes who are located or served through the affected infrastructure in Germany. Next Update by Microsoft not before 18:00pm / Tomorrow morning 08:00am.

Issue is still ongoing. Regarding to M365 Service Health, Microsoft is still trying to establish a fix. Next Update: 16:30

Issue is still ongoing. Regarding to M365 Service Health, Microsoft is trying to isolate the source of the issue and establish a fix. Next Update: 14:30