One unified email API across 18 providers (SMTP, Resend, SES, Postmark, SendGrid, Mailgun, …). Zero deps, RFC 8058 + DKIM ready, edge-first, strict TypeScript.

Self-hosted email sending platform built on Cloudflare Email Sending — REST API, admin UI, templates, domain management, scoped API keys, all in one Docker container.

SocketLabs Email Delivery .NET Client Library

Official Laravel integration for the Lettr email API

Self-hosted email API for developers free alternative to SendGrid/Resend

SocketLabs Email Delivery Go Client Library https://www.socketlabs.com

Laravel mail transport for Plunk API with attachments, event tracking, email verification, templates and self-hosted support

Playwright fixtures to easily integrate with MailHog

Go SDK for Amply

Compose, deliver, and test emails in Rust - pluggable providers with zero configuration

Official PHP SDK for the Lettr email API

Official Go SDK for the Lettr email API

MCP server for the Inxmail Commerce transactional API — events, sendings, bounces, blocklist, blacklist, reactions, and delivery tracking from Claude.

A collection of Free, open-source MJML email templates.

mjml-java: Zero-dependency Java renderer for MJML, enabling responsive email template creation. Open-source with MIT License.

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

Phoenix transactional email with preview/admin UI

Python SDK for Amply

Javascript SDK for Amply

HTML Email: Transactional based on Squarespaces's transaction email from https://files.reallygoodemails.com/emails/retention-email-design-from-squarespace.png