Microsoft 365 Alert : Service Degradation – Microsoft Exchange – Users may be unable to access Exchange Online through Outlook on the web, Exchange ActiveSync, and REST – RESOLVED
26/01/2022 07:43:00 AM (GMT)
Issue Reported : 25/01/2022 05:25:00 PM (UTC)
Microsoft Reference : EX318176
Issue Status: RESTORED
Issue Description: Users may be unable to access Exchange Online through Outlook on the web, Exchange ActiveSync, and REST
Scope of Impact : Any user attempting to access Exchange Online through any connection method may have experienced intermittent access issues
Final Update – 26/01/2022 07:43:00 AM : Disabling the feature that would reroute requests to alternate service infrastructure was unnecessary. Instead, Microsoft identified that a datacenter load balancing solution degradation led to an outage for cache that Exchange Online Client Access Front End (CAFE) infrastructure is reliant upon to properly route incoming requests to the service for certain protocols. They routed incoming requests to an alternate traffic management system and confirmed through service telemetry that this mitigated the impact.