From the forums: How to completely switch from Gmail to Outlook
As if you needed another reason why the Windows Phone Central forums are the best around. You can head there to find all sorts of information and perks. Sometimes developers will recruit users to test drive an upcoming app for them. You can also find the latest and greatest apps that nobody knows about or just kick it with like-minded smartphone users. Then there are times like today where you get awesome tutorials like this one to completely switch from Gmail to Outlook.
Forum member Jakeeeee has posted an easy to follow guide on migrating your life off Mountain Views servers to those in Redmond. The guide holds your hand as you transfer contacts, mail, calendar and documents to Microsoft’s services. Something we recommend doing if you’re using a Windows Phone. That way if Google pulls anymore stunts like dropping EAS support you won’t get stuck.
Hit up the thread right now in the forums to go through the process. While there be sure to poke around and check out other threads if you’re new.