I'm currently running a personal mailserver (hMailServer running on a Win2K box) for my family. In order to access email from the web, I've installed squirrelmail. But I've become increasingly frustrated with this webmail client. Even though it does what it's supposed, it lacks many of the features I've become addicted to like an advanced address book, threaded conversations, text completion when choosing who to send an email to. That sort of stuff.
While looking for alternatives, I came across Zimbra. From the demo the webmail client looks to be exactly what I want.

But I do have some questions:
1. Is it possible to only use the webmail client and not the entire suit?
2. Does this client run on a windows system? (I suppose I'd only need Tomcat or not even that?)

PS. I wasn't sure where to post this question, but migration seemed to be the most logical