Hi D3BR1S,
Thank you for your updates. To have better understanding of your situation, I’d like to collect some information for further troubleshooting:
1. Are there any forwarding rules or inbox rules have been applied to this user?
2. Do you have any mailbox Delegation settings of this account for other users?
3. Because the NDR in the post has been removed some information, to narrow down this issue, please provide the complete NDR for us.
Since this is your privacy, I will send a private message to you to request the NDR. To access the private message:
1. Please go to your details section on the right side of the community site.
2. Click Private messages.
3. Click the subject title of the response to read the message.
Thanks,
Edmond Peng