Well originally this post is meant to tell you that you can’t get “EMAIL address” through linkedin api.
However, you can get a number of other profile field which include:
- user id
- first name
- last name
- headline
- location
- industry
- current status
- connections
and so on.
You can get the full list of profile fields which linkedin API allows you to access through your application on this page: https://developer.linkedin.com/documents/profile-fields
About getting email id of that person, well you can ask him to enter his email to continue on a seeprate page.