There are two classes of user account, regular users and the postmaster.

Normal users can perform the following actions:
  Change their own password
  Manage redirects for their account

The Administrator can perform all actions.

Normally the administrative account name is "postmaster", however this is not always the case. If your are unsure, please contact the mail administrator for your domain.

Example:
User Name: postmaster
Domain Name: mydomain.com
Password: **********

The password given must be the valid passord for the user account.