Microsoft 365 Alert – Service Degradation – Exchange Online – Users intermittently see duplicate attachments in email messages received from senders utilizing Outlook on the web – RESOLVED

12/04/2023 14:20:00 PM (GMT)

NHSmail Reference : INC35298769

Microsoft Reference : EX540691

Issue Status : RESOLVED

Issue Description : Users intermittently see duplicate attachments in email messages received from senders utilizing Outlook on the web.

More Information : Users intermittently see duplicate attachments in email messages received from senders utilizing Outlook on the web.

Final Update : 24/04/2023 08:54:00 AM –After the initial investigation, Microsoft have assessed that a conflict in the Outlook on the web code base is causing rare duplications of email attachment requests, resulting in impact. It’s expected that users may intermittently see duplicate attachments in email messages received from senders utilizing Outlook on the web until a long-term fix that is developed to identify and remove duplicate attachment requests and repair this issue. Due to the complexity of the underlying code conflict, they anticipate that this fix will require significant time to complete. Your representatives have agreed to lower severity on the case while the fix is in development, and further updates will be provided via your support case. Please see your support case for additional insights. This communication will expire in 24 hours.

Scope of impact : Your organization is affected by this event, and all users intermittently see duplicate attachments in email messages received from senders utilizing Outlook on the web.

Root cause : A recent standard service update inadvertently contains an authentication code regression which is resulting in some users being unable to access or perform various Microsoft 365 group actions in the Outlook desktop client.