1. Login to http://mail.yourdomain.com as primary admin or systemadmin Note: The admin account can control everything for all users under the domain.
2. For admin password change Click on the settings then under administrators , select the admin account to perform admin password change.
3. Click Change Password, then fill in your old password and new password to make the changes
4. For users, click to 'Domain Settings'
5. Select the user you wish to change its password
6. After select the user, you will see these options, and select the “Change Password” option