Hi Brent, I didn’t think that was actually possible due to how BIS or BES interfaces with the Exchange mailbox.
Instead there are two workarounds I can think of:
Workaround #1: <a href=”http://www.blackberry.com/btsc/search.do?cmd=displayKC&docType=kc&externalId=KB10008&sliceId=SAL_Public&dialogID=151618731&stateId=0%200%2070521648″>Blackberry Doc ID : KB10008</a>
Workaround #2: Have one mailbox for each user to access shared mailbox
Mailbox 1 – The mailbox you want to sync with
Mailbox 2 – User 1 – Blackberry 1
Mailbox 3 – User 2 – Blackberry 2
Mailbox 4 – User 3 – Blackberry 3
Then create a distribution list with Mailbox 2, 3 and 4 in it.
Then forward a copy of the email from Mailbox 1 to the distribution list.
Then setup each BIS account to sync with one of each of the mailboxes. That should do the trick.