Microsoft 365 Alert : Service Degradation – Exchange Online – Recipients are unable to open encrypted email messages sent via Exchange Online – RESOLVED
29/12/2021 07:55:00 AM (GMT)
Issue Reported : 17/12/2021 07:28:00 AM (UTC)
Microsoft Reference : EX307758
Issue Status: RESTORED
Issue Description: Recipients are unable to open encrypted email messages sent via Exchange Online.
More info: Affected users may use a One Time Password (OTP) as an alternative method to open encrypted email messages.
Scope of impact: The issue may impact any users sending external encrypted email messages.
Final Update – 05/01/2022 07:40:00 AM: Microsoft confirmed that the fix has deployed to all affected infrastructure and validated that the fix has resolved this issue via telemetry and internal testing.