Google Contacts API gives client applications access to a user’s contacts list where the application can create new contacts, update or delete existing ones, or query for contacts that match particular criteria. This tutorial explains how to implement the API in C# and ASP.NET with OAuth 2.0.
Twilio SendGrid's Email Validation API is now publicly available. The API validates email addresses by searching in real-time for errors such as typos, inactive, non-existent, disposable and shared mailboxes. Further, the API checks for proper syntax, DNS records, disposable domains, and more.