Dec 15 2020 03:18 PM
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?
Dec 16 2020 01:47 AM
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