Mailgun - A set of powerful APIs that enable you to send, receive and track email from your app effortlessly whether you use Python, Ruby, PHP, C#, Node.js or Java.
Aritic Mail - Ariticmail is a transactional email delivery API for applications and enterprises.
SendGrid - Learn why more developers choose SendGrid for their email deliverability service to send transactional emails triggered by web apps. Get started for free
Vero - Email platform for product, marketing and engineering teams
EmailJS - Send email directly from your client-side Javascript code – no server side code required. Add static or dynamic attachments, dynamic parameters, captcha code and more. Start with our free tier!
RealTime Email - RealTime Email provides email relevance by enabling marketers to respond to each recipient’s personal context.