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.
Goto: http://www.whatsmydns.net
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!
IslandEarth 