Email Clients

novu

by novuhq

The open-source communication infrastructure for agents and products

PHPMailer

by PHPMailer

The classic email sending library for PHP

react-email

by resend

💌 Build and send emails using React

mjml

by mjmlio

MJML: the only framework that makes responsive email easy

Mailspring

by Foundry376

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

nodemailer

by nodemailer

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

BillionMail

by Billionmail

BillionMail gives you open-source MailServer, NewsLetter, Email Marketing — fully self-hosted, dev-friendly, and free from monthly fees. Join the discord:…

holehe

by megadose

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.

mailinabox

by mail-in-a-box

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.

cloud-mail

by maillab

An all-in-one email service platform powered by Cloudflare | 基于 Cloudflare 的一站式邮箱服务平台 | Cloudflare Email 邮箱 Mail

logto

by logto-io

🧑‍🚀 Authentication and authorization infrastructure for SaaS and AI apps, built on OIDC and OAuth 2.1 with multi-tenancy, SSO, and RBAC.

thunderbird-android

by thunderbird

Thunderbird for Android – Open Source Email App for Android (fka K-9 Mail)

responsive-html-email-template

by leemunroe

A free simple responsive HTML email template

LKY_OfficeTools

by OdysseusYuan

一键自动化 下载、安装、激活 Office 的利器。

inbox-zero

by elie222

The world's best AI personal assistant for email. Open source app to help you reach inbox zero fast.

cloudflare_temp_email

by dreamhunter2333

CloudFlare free temp domain email 免费收发 临时域名邮箱 支持附件 IMAP SMTP TelegramBot

EmailValidator

by egulias

PHP Email address validator

frappe

by frappe

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

Zero

by Mail-0

Experience email the way you want with Mail0 – the first open source email app that puts your privacy and safety first. Join the discord: https://mail0.link/discord

check-if-email-exists

by reacherhq

Check if an email address exists without sending any email, written in Rust. Comes with a ⚙️ HTTP backend.

alertmanager

by prometheus

Prometheus Alertmanager

tutanota

by tutao

Tuta 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.

Mailu

by Mailu

Insular email distribution - mail server as Docker images

himalaya

by pimalaya

CLI to manage emails

app

by simple-login

The SimpleLogin back-end and web app

MailKit

by jstedfast

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

maddy

by foxcpp

✉️ Composable all-in-one mail server.

mosint

by alpkeskin

An automated e-mail OSINT tool

macro

by macro-inc

Macro is a unified workspace for teams: email, chat, docs, tasks, agents, calls, and CRM — @-linked together with shared AI memory.

disposable-email-domains

by disposable-email-domains

a list of disposable email domains

mailflare

by hieunc229

Email for professionals and teams

h8mail

by khast3x

Email OSINT & Password breach hunting tool, locally or using premium services. Supports chasing down related email

react-email-editor

by unlayer

Drag-n-Drop Email Editor Component for React.js

Cerberus

by emailmonday

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

anonaddy

by anonaddy

Anonymous email forwarding

useSend

by usesend

Open source alternative to Resend, Sendgrid, Postmark etc.

Mocreak

by OdysseusYuan

Automatically downloads, installs, and deploys genuine Windows and Office with one click. This tool is completely free, ad-free, green, non-toxic, simple, efficient and safe.

FairEmail

by M66B

Fully featured, open source, privacy friendly email app for Android

awesome-newsletters

by zudochkin

A list of amazing Newsletters

heml

by SparkPost

HEML is an open source markup language for building responsive email.

notify

by nikoksr

A dead simple Go library for sending notifications to various messaging services.

message-pusher

by songquanpeng

搭建专属于你的消息推送服务，支持多种消息推送方式，支持 Markdown，基于 Golang 仅单可执行文件，开箱即用

neomutt

by neomutt

✉️ Teaching an Old Dog New Tricks -- IRC: #neomutt on irc.libera.chat

email-templates

by forwardemail

Create, preview (browser/iOS Simulator), and send custom email templates for Node.js. Made for @forwardemail, @ladjs, @cabinjs, @spamscanner, and @breejs.

modoboa

by modoboa

Mail hosting made simple

Papercut-SMTP

by ChangemakerStudios

Papercut SMTP -- The Simple Desktop Email Server

mail

by flectar

Built from the ground up for speed. Flectar Mail delivers native performance, instant startup, and as little as 80 MB of RAM.

Kanmail

by Oxygem

📥 Turn your inbox into a kanban board.

matcha

by floatpane

A beautiful and functional email client for your terminal, built with Go and the charming Bubble Tea TUI library. Never leave your command line to check your inbox or send an…

penguin-mail

by c9dev

Mail and calendar for Linux and macOS. Gmail and IMAP accounts, Google Calendar, contacts, OpenPGP and S/MIME. GTK4 and libadwaita, written in Rust.