Debian Email Setup

I have a new server and I need email set up for Debian Etch linux. I would like both webmail and pop3 mail set up to work. Right now, I have a test domain pointed to it, so I'll need to also know how to switch it to the live domain when we move our live site over as well as setup all our live email addresses via some kind of administration tool (preferably a web based one). I've previously tried to set up email myself using vpostmaster (which sets up squirrelmail, postfix, spamassassin and other things), but it seemed to have delays in processing email. Some emails would go through immediately while others would take a full day to get through. I need to make sure my final email system has standard immediate email delivery. Anything related to the original email I tried to set up can be wiped out / overwritten. However, I have many things related to my website on there which need to stay (mysql, php, apache, etc.. ) ## Deliverables Setup of working email pop3 email, webmail, spamassassin (or some spam blocking tool), and an account management system for email accounts.. ## Platform debian etch linux updated with apt-get.