# Email & Notification APIs

> Transactional email APIs, SMTP relays and multi-channel notification infrastructure. Marketing campaigns go to Email Marketing.

- Parent category: [Backend](https://devshelf.io/category/backend.md)
- DevShelf page: https://devshelf.io/category/email-notification-apis

## Resources (14)

- [Amazon Simple Email Service](https://devshelf.io/resource/amazon-simple-email-service.md): Cloud-based email sending and receiving service integrating via API or SMTP for transactional and marketing messages at scale. (pricing: not verified)
- [Customer.io](https://devshelf.io/resource/customer-io.md): A customer engagement platform for automating personalized messaging and lifecycle marketing based on behavioral data. (pricing: Paid)
- [Heybounce](https://devshelf.io/resource/heybounce.md): Email verification service for real-time validation, bulk list cleaning, and sender reputation protection. (pricing: Pay-as-you-go)
- [Knock](https://devshelf.io/resource/knock.md): Agentic customer engagement infrastructure for lifecycle and transactional messaging across email, in-app, push, SMS, and chat. (pricing: not verified)
- [Loops](https://devshelf.io/resource/loops.md): Email sending platform for SaaS teams to manage marketing, product, and transactional emails with API and workflow support. (pricing: Freemium)
- [MailerSend](https://devshelf.io/resource/mailersend.md): Developer-focused transactional email, SMS, and WhatsApp API and SMTP relay service with real-time delivery tracking and webhooks. (pricing: Freemium, Pay-as-you-go)
- [Mailgun](https://devshelf.io/resource/mailgun.md): Transactional email delivery service providing APIs for sending, validating, and optimizing email campaigns. (pricing: Freemium)
- [Novu](https://devshelf.io/resource/novu.md): Open-source communication infrastructure to notify users and connect AI agents across multiple messaging channels via a single API. (pricing: Freemium)
- [Plunk](https://devshelf.io/resource/plunk.md): Open-source transactional email platform supporting automated workflows, marketing campaigns, and unified contact management. (pricing: Freemium, Pay-as-you-go)
- [Postmark](https://devshelf.io/resource/postmark.md): Fast and reliable transactional email delivery service and API for developers, focusing on high inbox deliverability and message streams. (pricing: Freemium)
- [React Email](https://devshelf.io/resource/react-email.md): A collection of unstyled components for building emails using React, Tailwind CSS, and TypeScript with cross-client compatibility support. (pricing: Free)
- [Resend](https://devshelf.io/resource/resend.md): Email platform for developers to send transactional and marketing emails at scale with a focus on deliverability. (pricing: Freemium, Pay-as-you-go)
- [Truelist](https://devshelf.io/resource/truelist.md): Email validation platform to clean lists, verify addresses in real-time, and protect sender reputation. (pricing: Freemium)
- [Twilio](https://devshelf.io/resource/twilio.md): Cloud communications platform providing APIs for SMS, voice, email, and conversational AI services. (pricing: not verified)

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