Evaluating Open Sourced Web E-mail Projects?

malahoo asks: "I've recently registered my own domain name for personal fun and education, and am trying to find interesting things to do with it and my Linux box. High on this list is setting up a Web-based e-mail site, like YahooMail or Hotmail, for my family and friends to use. What open source projects out there would be suitable for this? On freshmeat, I've found such projects as WebMail, PHPWebMail, acmemail, etc. But I haven't found a way to evaluate these programs based on features, stability, security, and other factors. Have any of my fellow members of the Slashdot community set up a Web mail site? What tools did you use, how did you decide on these tools, and what is your experience & reccomendations for someone following the same path?"