Managing ActiveSync Mailboxes requires you to login as a "Domain Administrator". Here are the steps on how to do so :
1. Login to https://sm01.hostcentral.net using the "Administrator Login Information" provided in the welcome email.
2. After successfully logging in, click on "Domain Settings" -> "ActiveSync Mailboxes" on the left navigation bar.
3. Click on the "Add" button to add a new ActiveSync mailbox.
This mailbox must be a valid user account.
To see all valid user accounts, click on "Domain Settings" -> "Users" on the left navigation bar.
Likewise, to delete a ActiveSync mailbox, check the corresponding account and click the "Delete" button.
4. Click on the "Save" or "OK" button to save all your changes.
For further help, please refer to product documentation guide at http://help.smartertools.com/SmarterMail/v15/