I know mail/webmail servers deal nothing with apache directly.. but I dont know where else to ask on this forum.. now I have search and only found answers based on a *nix enviroment.

I am currently working with a NT based enviroment.. XP to be more exact..
I am currently hosting 3 domains and have 6 more on the way. and my biggest problem is I can not find a single webmail/mail server. That works on this OS, that supports multiple domains, with multiple users that can add there own accounts from a cpanel of any sort.. The only ones I found seem to work only within a network.. or just want to forward mail to another inbox system..

I need something that can store mails for users at domain1.com domain2.net etc.. as well as allow them to send mail via the same system. and have there logins be something like yourname1@domain1.com yourname1@domain2.net not just yourname1 for all domains..

Is there any free solutions out there? or any solutions at all for that matter?