sue mosher [mvp]

The other mailbox owner needs to grant you Reviewer permission to the root of the mailbox, as well as appropriate permission on the folder(s).

You then go into Tools | Services or Tools | E-mail Accounts, bring up the properties for the Exchange Server service, and on the Advanced tab, add the other mailbox.

After that, you will see in the folder list all those folders in the secondary mailbox to which he/she has access and can also see them when you add a contact link to a new item.
--
Sue Mosher, Outlook MVP
Outlook and Exchange solutions at http://www.slipstick.com
Author of
Microsoft Outlook Programming: Jumpstart
for Administrators, Power Users, and Developers
http://www.slipstick.com/books/jumpstart.htm

sue mosher [mvp]

The other mailbox owner needs to grant you Reviewer permission to the root of the mailbox, as well as appropriate permission on the folder(s).

You then go into Tools | Services or Tools | E-mail Accounts, bring up the properties for the Exchange Server service, and on the Advanced tab, add the other mailbox.

After that, you will see in the folder list all those folders in the secondary mailbox to which he/she has access and can also see them when you add a contact link to a new item.
--
Sue Mosher, Outlook MVP
Outlook and Exchange solutions at http://www.slipstick.com
Author of
Microsoft Outlook Programming: Jumpstart
for Administrators, Power Users, and Developers
http://www.slipstick.com/books/jumpstart.htm