I am facing the same issue, while the replies are being appended in
request and even SDP is sending notification to the requester those who
are requesting through email that your request cannot be processed
through email once I disabled request creation through email.
After finding this issue I did perform upgrade to version 9046 then
9047, but still the problem exists.
It's just causing confusion since the error message is not in
detail and the support team is asking the same as they asked you.
Please update if you get this issue resolved for you :)
Thanks,