Email bounce back?

Occasional Visitor

Hi!  I started receiving bounce back emails saying that the recipient's email is incorrect but we had previously been corresponding.  It is happening to multiple email threads.  Is there something I can do to fix this issue?

1 Reply

Posting the actual NDR message would help. You can also run a message trace to obtain additional details: Message trace in the Security & Compliance Center - Office 365 | Microsoft Docs