Hello experts. We have exchange 2013 cu15 currently in production serving 3 thousand users. This on prem exchange is using currently RPC over HTTPS with NTLM Outlook. We have outlook 2016. We plan on migrating to office 365 using hybrid migration. I know ExOnline uses MAPI over HTTPS with basic authentication. Will this be an issue for the users when we migrate them to office 365? Will there outlooks still be able to connect to ex online, or do we have to enable our on-prem exchange to use MAPI overHTTPS now for the migration to complete successfully?
Please let me know, and thanks in advance.