We are planning on migration from exchange 2007 to 2013. They will need to coexist till we move all the mailboxes.
Scenario 1:
4 Servers with all 4 having CAS/MB roles.
Kindly advise on the certification configuration to ensure they coexist with the exchange 2007.
Scenario 2:
4 servers with 1 server having CAS and 3 serverswith MB role.
Kindly advise on the certification configuration to ensure they coexist with the exchange 2007.