1. CAS/HUB Server: success2. Mailbox Server 1: success
3. Mailbox Server 2: Mailbox Role Failed. I’ve rebooted the server and tried restarting Exchange 2010 SP2 setup which resulted in the same error:
Exchange 2010 SP2 Setup failed with error:Couldn't resolve the user or group "AD-domain/Microsoft Exchange Security Groups/Discovery Management." If the user or group is a foreign forest principal, you must have either a two-way trust or an outgoing trust.
The trust relationship between the primary domain and the trusted domain failed.
Solution:1. Disable Discovery Search Mailbox
2. Enable Discovery Search Mailbox:
- Enable-Mailbox discoverysearch* -Discovery
- Give user(s) Full Access Permission on Discovery Search Mailbox