Suggestion about Mail system??

[realistic]

I have my own website where I want to set up mailing system like yahoo Google or msn. I do not understand where to start and what to start.

My server is debian Linux and I am running the script php on my server I need to integrate mail system with my php script. If you any one know any guide lines I can setup and good feature for my website.

[iioacademy]

There are few mail systems that run in php scripts.
You can use open source - no cost
or the paid one.