We are still waiting for a reply from our mass mail provider to resolve the issues. Meanwhile, we have switched the forums over to a different system as a temporary hotfix. This will allow the server to send automated messages again for the time being. The fix is not permanent, nor is it optimal and may not be stable all the time. But hopefully we will have a solution with our provider on the other side of the Easter holiday.
The elite site here has been switched over to a different mass mail system as well, separate from the forum. This change will be permanent, as it’s perfectly sufficient for the volumes of mails sent from here.