📫 Rails Engine to preview emails in the browser

The best email marketing services and tools help marketers save time and improve their results.

Email.Net is an email sender abstraction for .NET to decouple your email sending from the underlying provider, with access to different types of providers such as MailKit, SendGrid, MailGun, etc

AWS Lambda function that sends SES notifications to Elasticsearch

Official Laravel integration for the Lettr email API

Automated bulk email sender with Python, JSON queues, secure SMTP, HTML/attachments and full real-time logging. Envio massivo automatizado com Python, filas JSON, SMTP seguro, HTML/anexos e logs completos em tempo real.

Official Node.js SDK and CLI for the Lettr email API

Developer-friendly email delivery platform - Open alternative to Resend & SendGrid

Official PHP SDK for the Lettr email API

Scalable Reliable Mail Transfer Agent — high-performance MTA in Go with per-domain queues, DKIM/SPF/DMARC, bounce handling, rate limiting, and web dashboard. Modern alternative to Postfix and Exim.

Official Go SDK for the Lettr email API

🎄🎁 Random attribution of Secret Santas in a group via email, deletion of the sent emails. Can't cheat !

Official Python SDK for the Lettr email API

Automated backend workflow for retailer recommendations.

Multi-provider email delivery service with intelligent routing and automatic failover

A lightweight WordPress plugin that routes all outgoing wp_mail() email through the Resend transactional email API. Works as a clean SMTP alternative. No extra features, just reliable delivery.

Open-source SMTP email service and developer email API built for backend applications with reliable delivery, queueing, retries, and observability.

Lettr email API plugin for WordPress — reliable transactional email delivery without SMTP

Mail E2E Exporter is a Prometheus-compatible exporter that monitors the real end-to-end delivery path of emails: sending via SMTP and receiving via IMAP.