Not my design but its being forced on us. For whatever reason Exchange 2013 will be installed in its own accounts forest- call it staff.domain.com. Another forest - admin.domain.com will be set up for admin purposes only. Both are single domain single forests.
There will be a one way trust from staff.domain.com to admin.domain.com. The admin accounts will not be mail enabled and we will administer Exchange across forests.
The question is- what functionality will we lose if any? Will this work?