Recently changed my email over to Microsoft’s Office 365 which saved me about 2 thirds on what I was paying!
Migration went ok although I had to manually migrate using Outlook – export to PST from old account, import PST to new account etc.
One piece of advice they did give me was a DNS Propagation Checker that would check the propagation around the world when I changed over my DNS MX records to point to Ofifce 365.
To check an MX record change the pull down to MX and enter your domain name e.g. contoso.com, hit search and the map and table will give a green tick or a red x depending on status – invaluable!