I am using OAuth to access Gmail with dotNetOAuth. How can I force Google to return user's email address as part of callback after authorization?
By default, Google OAuth callback only returns the token secret and access tokens.
First you need to add the following scope (https://www.googleapis.com/auth/userinfo.email) to your oauth request.
After you're back to your app from Google and you have your access token, you can make a request using the access token to https://www.googleapis.com/userinfo/email?alt=json
.
This will return the email address. More info at http://sites.google.com/site/oauthgoog/Home/emaildisplayscope