Sorry about the multiple test emails that passed through. I thought they were still being rejected but a batch went through as a group.
In the interest of not continuing to spam the list as well as getting on with other business, I'm going to stop testing for now. I think that I've narrowed down the problematic email filters on the list to 2 possibilities. In the future if an email gets held for moderation or rejected, at least we now have a good idea of where to start looking.
Thanks again for your patience,
Pine