Losing my mind with GoDaddy Defederation and Proofpoint
We have a client who used GoDaddy for M365 and had their "Advanced Email Security" i.e. Proofpoint Essentials. We defederated their account from Godaddy almost 6+ months ago and have not had issues till recently. One of their customers who also uses GoDaddy and Advanced Email Security keeps getting a bounce back saying 550 5.7.1 Recipient address rejected: User email address is marked as invalid and it is referencing proofpoint. On our clients end their is no MX record, connector, mailbox rule, transport rule, enterprise app, anything related to proofpoint anymore. So my only thought is that it has to be something that is messed up or leftover in Proofpoint that only GoDaddy support can clear out. Godaddy has said that their proofpoint account has been deleted but something is still causing this issue. I've called about 6 times and spent over 8 hours (mostly on hold) with GoDaddy. This last time they told me to reset his Microsoft password as it would release the domain which makes no sense. Has anyone had this issue before? I'm tempted to start looking for jobs at GoDaddy just to fix this problem then quit.