we have a forest with two trees that hold one domain each. There is a default tree-root trust (transitive, two-way) between the top domains. Since both trees are in the same forest they share the same global catalog and schema. The relevant exchange mailboxes and most users are held in the forest root domain (lets call it tree-root-1). Less then 5% of the users are held in the other tree-root domain (lets call it tree-root-2).
We configured a button in Adaxes to manage the "Send on behalf of" and "Full Access" properties in Exchange. We used the built-in functionality from Adaxes. The buttons work fine. there is just one problem: If we try to give a user from tree-root-2 "Send on Behalf of" permissions to a mailbox in tree-root-1 we fail, because the 'Look-In" box in the web interface will not allow us to choose anything but tree-root-1 (the forest root domain). When using the "Full-Access" button the "Look-In" box allows us to chose between "Everywhere" and tree-root-1.
Please also see the two attached pictures.
Where can we configure the "Send on Behalf of" function to also use "Everywhere" in the Look-In box?
Thank you for your suggestions!