Enhance the Gmail and Inbox experience
Use the Gmail REST API to add Gmail features to your app, granting it access to threads, messages, labels, drafts, and history. The API is easy to use with modern web languages and Google API client libraries.
Create a Gmail Add-on to let your users interact with your apps and services directly—without ever leaving Gmail. You use Apps Script to create an add-on that can extend Gmail behavior, add functionality, and connect to other G Suite products like Google Calendar.

Design
Create engaging and responsive emails for your customers using CSS.
Interact
Allow your app to send emails that expose interactions in Gmail, Inbox, Google Search, and the Google app.
Manage
Connect your alternative email client with Gmail user accounts, using industry standard IMAP and SMTP protocols.