Step by Step upgrade exchange 2013 CU20 -> CU23

[Tien Ngo Thanh]

current my system have 4 mailbox (CAS+MBX) exchange 2013 CU20 and 2 server edge . we have running hybrid email with office365. Now we want upgrade to CU23 lastest version. please help upgrade this

need extend schemas ? if no , then i only need update one by one all mailbox, after that to two edge ?

[#2]

@Tien Ngo Thanh 

There are schema changes when updating from Exchange 2013 CU 20 to CU 23.  Your update order will be mailbox server first, then the edge servers last.