Sorry for the email problems! In my initial test of the email address, there was an error, so we needed to re-submit the test to the destination email address (firstname.lastname@example.org). The subsequent test proved that the email server was working fine. The test verifies if mail being sent from the server is bouncing from the destination email server. In this case, it was not bouncing. Bounce-back emails indicate the specific problem with delivery as indicated by the email server. This could indicate that the server might have been initially blocked, but it may then been removed from the blacklist after the server IP was changed. Our Systems team continually monitors the mail servers, so it's very possible that you might be looking at a problem that has already been corrected.
For more information, please see Why does Email bounce - bounceback, or error? I hope this helps to clarify the issue! Please let us know if you require any further assistance.
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