One question that comes up constantly from clients is “Once we move all mailboxes to exchange online, we can remove all our exchange servers, right ?”

To which we answer “no – for these reasons….” but its something that has a great deal of trouble sticking…. as the same question gets asked over and over again… sometimes by the same client, sometimes even by the same people.

I stumbled across this today – an article written a few months back which nicely lays out the possible scenario’s

https://docs.microsoft.com/en-us/exchange/decommission-on-premises-exchange

well done to the authors for laying it out plainly!

We don’t really work with any places that will be in scenario 1 anytime soon… but scenario 2 and 3 are spot on… with 3 being the most common scenario for our clients.