Microsoft 365 Alert – Service Degradation – Exchange Online – Users’ Office Message Encryption (OME) email messages sent through Exchange Online can’t be opened by some recipients -RESOLVED

24/04/2023 08:50:00 AM (GMT)

NHSmail Reference : INC35551548

Microsoft Reference : EX547161

Issue Status : RESOLVED

Issue Description : Users’ Office Message Encryption (OME) email messages sent through Exchange Online can’t be opened by some recipients.

More Information : This issue prevented recipients that use third-party email clients from opening the encrypted email messages. The recipient may have received the OME email messages but attempts to open the message were met with continuous loading prompts.refore they recommend that users try again if they’re redirected to the Outlook login page.

Final Update : 28/04/2023 11:42:00 AM – Microsoft have completed the redeployment of the recent Exchange Online update and confirmed with affected users that impact is remediated. Some users will need to clear their browser’s cache before they are able to access OME email messages.

Scope of impact : Impact was specific to users sending OME email messages who were served through the affected infrastructure and their recipients that used third-party email clients.

Root cause : A recent update to Exchange Online wasn’t properly deployed to the affected environment and was missing some scripts necessary to facilitate access to encrypted email, resulting in impact.

Next steps : Microsoft are reviewing the infrastructure responsible for deploying updates to Exchange Online to identify where the failure occurred within the deployment process, allowing us to prevent similar impact in the future.