Please use Roundcube to access your HyperSurf webmail:

Note: We have upgraded our webmail system. Horde and SquirrelMail are no longer available. Please use Roundcube going forward. If you have any questions, please contact support.

Once you login, please make sure you go to Settings and fill in the values for "Your Name" and "Your Email Address" — recipients may not receive your emails if you do not set the correct values.