Question : How Can an Admin Grant Read Permissions to Another User's Mailbox?

How can an Exchange 2007 admin grant a user only Read permissions to another user's mailbox?

This cmdlet works but gives full access which is not desired:
add-mailboxpermission -identity username.withmailbox -user username.wantstoreadmailbox -accessrights fullaccess

This cmdlet fails to allow the user to open the mailbox:
add-mailboxpermission -identity username.withmailbox -user username.wantstoreadmailbox -accessrights readpermission

I have searched Technet and with Google far and wide and it seems examples of granting rights to a mailbox always gives an example using FullAccess. How do you grant only Read permissions?

Answer : How Can an Admin Grant Read Permissions to Another User's Mailbox?

Hi,

I don't think you can assign permissions to review/read only via this method. You would need to use the delegate option or a tool like pfdavadmin to set reviewer permissions on the mailbox folders that the user needs read only access to.

Via the AD/Exchange permissions level its full access or nothing to open a mailbox. Using delegates/pfdavadmin is a MAPI operation which allows more granular control.

http://msexchangeteam.com/archive/2006/06/13/427944.aspx