I am looking at the following link and am confused by some of the information.
https://docs.microsoft.com/en-us/answers/questions/106570/upgrade-from-exchange-2013-to-exchange-2019.html
Specifically:
2) Make sure, CAS servers are also in the same CU22, as the minimum CU required for coexistence is Exchange 2013 CU21 & above
(What is a CAS Server? I am on exchange2013 CU21...)
3) Install the Exchange 2019 latest CU (Can I install Exchange 2019 latest CU while running 2013 CU 21? , These are on completely separate servers.)
4) Configure the certificates, URL's, connectors (Is there some sort of export tool for certs?)
5) Create a test mailbox in Exchange 2019 and test the client connectivity and mail flow (internal/external/exchange 2013) (I am not sure what this actually means??)
Thanks for any help with the above.
Is there any kind of migration path check list I can follow?
Thanks, B


