识别用户的简单方法是在Gmail中拥有该帐户？

Question

Do any one say which is the simple way to identify the user is having the account in Gmail ?

Answer 1

You cannot automatically determine whether an arbitrary user has a Gmail account.

Instead, you can ask the user:

<input type="checkbox" name="HasGmail" />
<label for="HasGmail">Do you have a Gmail account?</label>