A second choice for your webmail client has been installed on the Raincross servers. We had been using Squirrelmail for quite some time, but RoundCube is a nicely laid-out Web2.0 Email client that is in my opinion much nicer to use.
From the website:
RoundCube Webmail is a browser-based multilingual IMAP client with an application-like user interface. It provides full functionality you expect from an e-mail client, including MIME support, address book, folder manipulation, message searching and spell checking. RoundCube Webmail is written in PHP and requires the MySQL database. The user interface is fully skinnable using XHTML and CSS 2.
Please feel free to try it out for yourself by clicking on the link above, or here.
If you have a lot of addresses in Squirrelmail that you would like imported into RoundCube, send a support request in to support@raincross-tech.com