Your email is accessible via any web browser by tacking on /webmail/ to your domain name. eg. http://www.yourdomain.com/webmail/
After logging in using your email address and your password, you will be given a choice of webmail clients.
Horde is a more complex web application offering calendaring, address books and more as well as mail. It's useful if you work in groups.
SquirrelMail is a lightweight interface to your mail and particularly suited to slower connections such as mobile phones. Nothing but the basics.
Roundcube is a rich AJAX driven webmail application which may be familiar to people who use Google Mail in operation.
You can choose which webmail client loads by default be enabling autoload on the client of your choice.
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