Mailboxes can only be forwarded to one recipient. To forward a mailbox to multiple recipients you must create a DL (Distribution List) and forward the mailbox there.

1.  Login to the Web Administration tool
2.  Click Distribution Lists from the Admin Actions menu on the left
3.  Click Create Distribution List
4.  Choose a Display Name and Email Address for the new list.
5.  Select the Members Tab.
6.  Add the Mailbox, Distribution List or External Contacts you want messages forwarded to.
7.  Select the Delivery Restrictions tab.
8.  Check the From Authenticated users only box and select the option Only from.
9.  Choose the user who the mailbox is forwarded from and click Add.
10.  Click Mailboxes from the Admin Actions menu on the left.
11.  Select the Mailbox you wish to forward.
12.  Select the Delivery Options tab and select Forward to.
13.  Select our previously created distribution list from the list of choices.
14.  Click Save Changes

*Please note that the creation of a new Distribution List will be viewable in the Global Address List.  If you wish to hide the DL from the GAL, please contact with the name of the DL.  Hiding the DL will keep the function of the DL, but will not be searchable in the GAL.