Hi Matt, please use the debian users list and not the mentors list.
Besides, the exim users list can help you and the FAQ on www.exim.org is quite extensive. To do troubleshooting you need the output of a frozen message (get it with mailq) and force delivery with "exim -v -M <id>" and have that as information to others ready and they can help you way better. But, still, this is the completely wrong list. Regards, Alexander