Microsoft have now resolved the issue. Root cause analysis identified an issue with a specific section of the mailbox database infrastructure. This section was restarted and is now working correctly again.
Microsoft are now analysing performance data on the affected area to prevent this happening again.
We have found that in some cases users have required to log off of their sessions and to log back on again, to get the connection working correctly again.
To further update, Microsoft have since upgraded this issue from advisory priority to an incent status. We are continuing to monitor the situation and will provide a further update as soon as one becomes available.
We are aware of general Outlook connectivity issues at present. Microsoft have reported that an ongoing investigation is underway into the messaging API. Users may experience long waiting times trying to open Microsoft Outlook, with the application appearing to hang on the splash screen.
Microsoft have advised that a further update will be provided by 12:30. If we receive anything prior to this, we will pass this information on.
Disconnection issues were resolved.
We have been made aware of certain users may be unable to send Exchange Online email messages. Affected users may receive the following error “503 5.5.1 bad sequence of commands”
The issue is currently with Microsoft who are reviewing service monitoring telemetry to isolate the root cause and develop a remediation plan.
We expect an update on the matter from Microsoft at 10:30 AM
Please be aware that the remediation work has now concluded and services have now been fully restored. All client platforms are once again fully operational. We will continue to monitor the platform following this.