EmailEngine is a self-hosted email API. It connects to any email account over IMAP/SMTP, the Gmail API or Microsoft Graph and exposes all of them through one REST API, with real-time webhooks for new, changed and deleted messages, bounces and sent mail. Developers use it to sync their users' mailboxes into their own product and send email on the users' behalf, without writing IMAP, MIME or OAuth2 code themselves. Built by Postal Systems, the team behind Nodemailer.