Hello,
My ex customer has hosted their entire email infra with Microsoft office 365 cloud. They are thinking of migrating it back and hosting it back on premises. Please note it is not a Hybrid setup and customer do not have any presence of exchange servers in the environment. The users use single sign on to logon with their AD credentials to access the mailbox hosted at office 365 using ADFS trust.
Now customers wants to hosts exchange in house with and move the mailboxes back, possibly with zero downtime to users. What are the best possible options out here and how to introduce exchange 2013 into the environment without disturbing the current email access and flow.
Thanks