UPDATE – 2nd March 7:29am
Emails bouncing to Microsoft 365 recipients [Resolved]

Microsoft have confirmed that mail flow has now returned to normal.

Summary of issue: The issue occurred between circa 1600-2100 on the 1st March, on occasions, when sending to mailboxes on Microsoft 365 Tenants, a bounce back message would be received and the mail would not arrive at the recipients mailbox. If you received a bounce, please resend these mails.

Further updates can be found on Twitter

https://twitter.com/MSFT365Status/status/1631036581648687106?cxt=HHwWhICzjaTIzaItAAAA

———

Alert: Emails are bouncing to 365 recipients

Occasionally when sending to mailboxes on 365 you may find the emails bounce. Microsoft have recognised this as an issue and are investigating.

We will issue an update when we have further news.

Best

Knowall Support Team