I'm not really sure what to ask here but I'll describe what I'm doing and what I'm looking to do and perhaps someone can help out.

I'm a programmer but I come from a Windows environment. I've had a lot of programming experience but don't really know much about administering servers.

Anyway, I'm writing a small application that will act as an ASP for a reasonably small number of people. The application allows them to manage their art, up load pictures, set up galleries, that kind of thing.
The application is written in PHP and uses MySQL for it's backend. It's going to be hosted on a RedHat 9.0 server with Apache.

Although the users will never have actual accounts on the server (their experience happens through the administration functions supplied by the application) I wanted them to be able to have domains and e-mail off the server.

So, for example, they set up an account, upload some art, create a few galleries and a home page. Then they register mygreatart.com. I want to be able to have mygreatart.com point to their home page. I also want to give them say 5 to 10 e-mail accounts at mygreatart.com.

I'm wondering how I do this. I'm assuming I need some kind of software but I'm not sure what kind (actually I've got an idea for the e-mail but it seems overly complex).

Any help here would be greatly appreciated.

Thanks
Dale Cook