Microsoft Email Suspation

Question

Dear Microsoft,

I would like to know about email system. Now we received many suspation mail from one member but She didn't know everything about this. This is very important for us because mail arrived to all organization member and some read it. We urgently need to solve / troubleshoot this case. thank you.

Answer 1

Hi @ IT Support

Welcome to our forum!

Does the error occur recently? If so, is there any specific operation did you do before the error occurred?

And what is your account? An Exchange online account or something else?

As i known, The destination email server that generated the 5.1.0 error won't accept messages from you (the sender) or messages for the recipient. This can happen if messages from you (your email address, your Exchange Online organization, or even all of Exchange Online) are being blocked by the recipient.

If you are using an Exchange account, you may try the following steps, more information: Fix NDR error 550 5.1.0 in Exchange Online - Exchange | Microsoft Learn

In addition, to protect your domain details, we have removed some personal information from your post. In order to avoid privacy leakage, please remember to hide your personal information when you post next time.

Hope it helps!

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