- Enable Outlook Anywhere on Exchange 2010 and 2016
- Redirect: mail, and autodiscover to Exchange 2016, leave casarray.domain.local DNS record pointing to Exchange 2010.
- CasArray: CasArray DNS Record will still use the Exchange 2010 (direct RPC will still connect to the CasArray)
- When migrating mailboxes to Exchange 2016, default MAPI over HTTP will kick in, and Outlook Anywhere on Exchange 201o will comes to life.