Microsoft 365 Alert – Service Degradation – Exchange Online – Some users may be unable to access their mailbox using the IMAP4 connection method within Exchange Online – RESOLVED

Announcements Habiba Tabasum

11/08/2023 11:06:00 AM (GMT)

NHSmail Reference : INC37592201

Microsoft Reference : EX666988

Issue Status : RESOLVED

Issue Description : Users may be unable to access their mailbox using the IMAP4 connection method within Exchange Online.

More info : All other connection methods are unaffected by this issue.

Final Update : 11/08/2023 16:26:00 PM – The fix has successfully completed and previously affected users have confirmed that impact has been resolved.

Scope of impact : Impact is specific to users hosted through the affected infrastructure and may impact any user attempting to access their mailbox using the Internet Message Access Protocol (IMAP4) connection method within Exchange Online.

Root cause : A configuration issue within a recent change to enhance the IMAP4 connection method, is inadvertently causing impact.

Next steps : Microsoft are reviewing their IMAP4 configuration update procedures to help prevent this problem from happening again.