We're in the middle of migrating mailboxes from Exchange 2010 to Exchange 2013. Many of our users have Auto-Mapped mailboxes as well. In my testing, I've found that I cannot Auto-Map a mailbox that's on Exchange 2013 in a Exchange 2010 mailbox. I can manually
add it and it works fine. Is this by design with this type of coexistence or is there a fix for it? Our current Exchange 2010 environment is at SP3 with UR2.
Orange County District Attorney