We did indeed, finally, thankfully, get rid of our exchange server – and moved several systems to The Cloud: e-mail, accounting, and back-up. We are very happy with all of our researched choices for software-as-a-service (SaaS) providers.
We registered with Microsoft 360 for our virtual e-mail exchange service. Our e-mail easily synchronized between our desktops, laptops, and smart-phones. Out IT consultant liked it so much he signed up! There was a brief one-day outage early on, but that was it for the first year. One hidden kicker: be sure to set up your password to “never expire”.