I am setting up a Linux server and would like some advice on which options to choose.

Amongst other things I would like it to be a mail server which allows users to relay their mail with the sufficient authentication and I would also like to use POP3 which would also allow for easy integration for example with a webmail CGI interface perhaps.

At the moment, I am trying to decide which SMTP daemon to use but having trouble finding out exactly what they do without having to read the documents and learn them inside out first.

I would like something simple that would allow me to use aliases with some form of regular expression.

I am very concerned about using system users for email, I think this is just retarded for my setup. I would like a system with it's own set of separate user credentials.

For aliases I would like something that when a user is created doesn't do the retarded thing of making a default alias user@domain but has none.

Also I would like something that I can dictate where an anonomous sender can send to, point aliases to multiple users (perhaps through groups) and be able to use something forexample like alias Orakio*@domain to make all mail with the username begining with mine go to my account.

I also have multiple domains and want to be able to put domains in the aliases or match expressions.

Anyway the important thing is that I don't want to user system users.

Can anyone make any suggestions?

If you want easy to setup, use and configure, I'd probably say go with postfix as your mail agent.

I specified what I want. The question is not easy or hard but possible or impossible, can it be setup to do what I desire? If it can, and can be done so easily, even better.