ISPs in Louisiana and Mississippi Do Not CHOOSE AT&T

I am currently setting up email hosting for a client of mine.  They have a Small Business Server and want to host their own email.  Not to get too technical but when you do this, you call up the ISP (Internet Service Provider) and make sure that their Reverse DNS Points to your server.  Every time I have to deal BellSouth, now AT&T, this is a nightmare.  As I write this, I have been transferred for the 10 times (1 Hour) and no one could help me.  When I call Cox Tech support to do this, it takes 1 call.