As the reseller, you can set a mailbox forward on behalf of your customer.
*Please Note: If you want to forward an email to a mailbox outside of the network, you will first need to create a Contact containing the external mailbox address. Once the contact is added, it will then show up in the drop-down menu for forwarding mail. For more information, click the link on How to Create a Contact.
4. Now that you are logged in as the customer, navigate to the User List under My users.
5. From the User List, choose the mailbox you need to assign another user access rights to and click on Edit User.
5. Under the Microsoft Exchange service tab, select Forwarding Management. From here you will need to Load the Address Book for a list of available Exchange users. To enable mailbox forwarding, choose the mailbox, contact, or Distribution List by pressing the Select the link next to forwarding Emails to.
* Select Leave a copy in the mailbox if you wish to maintain a copy of all messages that are forwarded out. Smaller quota mailboxes can fill up quickly if not managed.
** Selecting Mailbox is Hidden will not only hide this mailbox from the Global Address List but will also hinder the configuration of an Email Program using the Outlook Anywhere feature. This option by default is disabled.
6. Select Save Changes when finished.