The receiving email server outside office 365 reported an error

We started getting compliant from multiple users telling us that their email messages are being bounced back from known recipients. I confirm with the Office 365 Bounce back message. In every case, the attached image is show, indicating that it’s an issue with the recipient’s email server, pointing to the troubleshooting link. It seems very unlikely that all of these clients with no connection (other than we are the one’s emailing them all) report this exact issue and at random. Can anyone offer any insight on this? Could these messages be getting flagged for certain keywords, or requirements met (BCC Bulk, etc)? If this is the case, how can I test/fix it?

Based on the details you provided, that IP in that message is what is blacklisted:

If that is your IP it appears to have some spam issues. GoDaddy has no control over the blacklists or how they gather their data. You can learn more on the above site.

What you can do now is follow the DETAILS buttons on the above page and put in manual requests to have your IP removed.

However, if it is a shared IP, there could be bad actors also using that IP that could cause this. In that case, you’ll want to see about getting a dedicated IP to minimize this from happening again.

HTH! :winking_face:

Hey there!
Try the link given by this user