Is your public IP on a residential or commercial IP block?  Hosting mail on a residential address is a constant nightmare keeping up with blacklists, and even then there are some systems you just can't reach.

 

I think there are several of us who could spare the bandwidth to run the server, but I think if we can find a presence in commercial space it will lend an air of professionalism to the group, and avoid the "some guy's basement" stigma, however unfair that would be.