💌 An extensible desktop mail app built on the modern web. Forks welcome!

The open-source notification infrastructure with fully functional embedded notification center

😱 Falsehoods Programmers Believe in

The classic email sending library for PHP

✉️ Send e-mails with Node.JS – easy as cake!

MJML: the only framework that makes responsive-email easy

💌 A beautiful, fast and fully open source mail client for Mac, Windows and Linux.

A free simple responsive HTML email template

Mail-in-a-Box helps individuals take back control of their email by defining a one-click, easy-to-deploy SMTP+everything else server: a mail server in a box.

PHP Email address validator

Comprehensive mailing tools for PHP

K-9 Mail – Open Source Email App for Android

Free and Open Source messaging and emailing app that combines common web applications into one.

🧑‍🚀 Logto is a modern Auth0 alternative for building identity infrastructure with minimal effort, for both your customers and their organizations.

Prometheus Alertmanager

Low code web framework for real world applications, in Python and Javascript

A cross-platform .NET library for IMAP, POP3, and SMTP.

holehe allows you to check if the mail is used on different sites like twitter, instagram and will retrieve information on sites with the forgotten password function.

Tutanota is an email service with a strong focus on security and privacy that lets you encrypt emails, contacts and calendar entries on all your devices.

A few simple, but solid patterns for responsive HTML email templates and newsletters. Even in Outlook and Gmail.