I am with a small company with legacy Exchange support from GoDaddy (and now with Office 365 for Business Essentials).
We are not happy with Exchange hosting / Office 365 with GoDaddy any more. They require us to login multiple times during the day through their portal, disrupting OneDrive, Outlook, etc. whereas Microsoft, when using them directly, does not seem to have these issues (I manage a couple of other Office 365 installations for a couple of non-profits which work great).
It's getting to the point now where the boss is ready to cutover from GoDaddy despite the fact we have an additional 18 months left of service with them.
We have a relatively small footprint with OneDrive accounts and SharePoint sites (SharePoint, Planner, Groups), but we have some infrastructure there.
We do have many years worth of e-mail in a couple of accounts on the Exchange server which we do not want to lose, and we would like to have a seamless transition of e-mail so that our clients and staff are not impacted.
Anyone who has done this have any experience and pointers you can provide?