Open Source Webmail

[robertlaferla at attbi.com (Robert La Ferla)]

As you probably have heard, the fine folks at AT&T Broadband are going 
to force us loyal serfs to switch our e-mail addresses to comcast.net. 
 Since I don't like having to switch my e-mail address every few months, 
I am going to set up my own domain.  However, I would like to be able to 
remotely view and compose e-mails from a web-based client in addition to 
POP/IMAP.  Does anyone know of or better yet have experience with an 
open source web-based e-mail system for Linux?

Robert