Hi, @MoeKd. We received a permanent delivering failure for that email address on 2024-10-02. When this happens we put the email address on a suppression list to comply with anti-spam regulations and policies.
I have removed the domain from this list so emails should begin sending correctly again now. However, if they do not, please let us know with a reply here.
By the way, I have deleted the other topic with the same question and we would ask you to please not cross-post the same issue in multiple topics going forward. (It is no big deal if it happens once but it does slow us down when it happens.)