Lovely idea... maybe not
The general problem with most ISPs offering any sort of service is competence.
Most of them have lost local skills required to run a service that is heavily reliant on sysadmin competence. The days when an ISP sysadmin could setup and manage mail, hosting, etc with their eyes closed are long gone. There is noone to do that any more. It is all a resale of somebody's else (usually the Big 3 +/- Yahoo) product.
There are a couple of notable exceptions per country, but that's about it. It is a desert out there.