E-mail en berichten

All-in-one mail server with JMAP, IMAP4, and SMTP support and a wide range of modern features.

Scalable MQTT broker. Connect 100M+ IoT devices in one single cluster, move and process real-time IoT data with 1M msg/s throughput at 1ms latency.

The most private and secure chat and applications platform - now with double ratchet E2E encryption.

Mail server suite based on Dovecot, Postfix and other open source software, that provides a modern Web UI for administration.

Complete and fully featured mail server for use by websites & web servers.

Production-ready fullstack but simple mail server (SMTP, IMAP, LDAP, Antispam, Antivirus, etc.) running inside a container. Only configuration files, no SQL database.

POP/IMAP/SMTP/Caldav/Carddav/LDAP exchange gateway allowing users to use any mail/calendar client with an Exchange server, even from the internet or behind a firewall through Outlook Web Access.

XMPP instant messaging server.

Email archiving server that syncs from IMAP accounts, indexes emails for full-text search, and provides a REST API. No external database required, includes WebUI with multi-account support.

XMPP server implementation in Java.

短信转发器——监控Android手机短信、来电、APP通知，并根据指定规则转发到其他手机：钉钉群自定义机器人、钉钉企业内机器人、企业微信群机器人、飞书机器人、企业微信应用消息、邮箱、bark、webhook、Telegram机器人、Server酱、PushPlus、手机短信等。包括主动控制服务端与客户端，让你轻松远程发短信、查短信、查通话、查话簿、查电量等。（V3.0 新增）PS.这个APK主要是学习与自用，如有BUG请提ISSUE，同时欢迎大家提PR指正

High performance, self-hosted newsletter and mailing list manager with a modern dashboard.

High-Performance server for NATS.io, the cloud and edge native messaging system.

Open source email alias solution to protect your email address. Comes with browser extensions and mobile apps.

Apache Kafka® running on Kubernetes

Apache RocketMQ is a cloud native messaging and streaming platform, making it simple to build event-driven applications.

Apache Pulsar - distributed pub-sub messaging system

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

Fast, highly extensible, and event driven SMTP server.

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

Feed reader for your email accounts.

Notification infrastructure for developers.

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

Turns any Ubuntu server into a fully functional mail server with one command.

CLI to manage emails

All-in-one mail server that implements SMTP (both MTA and MX) and IMAP. Replaces Postfix, Dovecot, OpenDKIM, OpenSPF, OpenDMARC with single daemon.

Email forwarding service for creating aliases.

IoT Platform Framework

An ultra-lightweight and blazing-fast Messaging Bus/MQTT Broker for Edge & SDV

Language-agnostic real-time messaging (Websocket or SockJS) server.

Simple yet full-featured mail server as a set of Docker images.

bluetooth mesh chat, IRC vibes

The classic email sending library for PHP

Mail hosting and management platform including a modern and simplified web user interface.

Lightweight, self-hosted, open-source chat server with voice, video, text, and screen sharing. Built for small groups who want privacy, simplicity, and full control over their data.

💌 Build and send emails using React

IM Chat OpenClaw

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.

signal-cli provides an unofficial commandline, JSON-RPC and dbus interface for the Signal messenger.

Open source alternative to Resend, Sendgrid, Postmark etc.

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

A Cloudflare-based email service | 基于 Cloudflare 的邮箱服务 | Cloudflare Email 邮箱 Mail

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

An OOB interaction gathering server and client library

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

Email for professionals and teams

Graphical client for the Soulseek peer-to-peer network

Apache ActiveMQ

Knock-Knock: A Live, Multi-Protocol Honeypot Dashboard of Internet Break-in Attempts - 13 Protocols, an Extensible Framework, and a Threat-Intelligence Database Serving a Public IP Blocklist Feed

Omni-channel customer engagement and messaging automation platform (alternative to Braze, Customer.io, Iterable).

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

Markdown-first CMS for bloggers, minimalists and startups. Open Source alternative to Medium, Mailchimp and Substack - https://markdown.ninja

Prometheus Alertmanager

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

Apache Iggy: Hyper-Efficient Message Streaming at Laser Speed

Share sensitive information securely with self-destructing links that are only viewable once.

Privacy-focused encrypted email for everyone. All-in-one alternative to Gmail + Mailchimp + Sendgrid.

Decentralized private messenger with chat-shared tools and games for Desktop

IMAP and POP3 server written primarily with security in mind.

Open source RabbitMQ: core server and tier 1 (built-in) plugins

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

Efficient reliable UDP unicast, UDP multicast, and IPC message transport

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

Messaging library for Python.

Telegram Server written in C# (Unofficial) - messaging, channels, media, secret chats and voice/video calls.

A distributed MQTT message broker based on Erlang/OTP. Built for high quality & Industrial use cases. The VerneMQ mission is active & the project maintained. Thank you for your support!

MJML: the only framework that makes responsive email easy

:mailbox: SMTP Server + Web Interface for viewing and testing emails during development.

Event-driven networking engine written in Python.

An easy to use .NET API for RabbitMQ

In-memory message queue with an Amazon SQS-compatible interface. Runs stand-alone or embedded.

A modern high-performance open source message queuing system

This is an Open source intelligent framework ie an osint tool which gathers valid information about a phone number, user's email address, perform VIN Osint, and reverse, perform subdomain enumeration, able to find email from a name, and so much more. Best osint tool for Termux and linux

Decentralized private messenger with chat-shared tools and games for Android

A high-speed covert tunnel that disguises TCP traffic as SMTP email communication to bypass Deep Packet Inspection (DPI) firewalls.

Mobile messaging platform with a focus on performance and scalability.

WhatsApp desktop application written in PyQt6 + PyQt6-WebEngine.

Rust client for NATS, the cloud native messaging system.

An IMAP/POP/SMTP proxy that transparently adds OAuth 2.0 authentication for email clients that don't support this method. Keep legacy email clients working with Exchange Online, Gmail and other providers.

MIT-licensed, COM-free .NET libraries for creating, reading, editing, converting, rendering, and extracting Office, PDF, email, OneNote, and text formats.

HiveMQ CE is a Java-based open source MQTT broker that fully supports MQTT 3.x and MQTT 5. It is the foundation of the HiveMQ Enterprise Connectivity and Messaging Platform

Papercut SMTP -- The Simple Desktop Email Server

RocketMQ企业级一站式服务平台

Pluggable foundation blocks for building distributed apps.

Email tracker, read receipt and spy pixel blocker plugin for macOS Mail (10.11-13.x)

Apache Artemis

Tinode chat client application for Android

A cute temporary email service built with NextJS + Cloudflare technology stack 🎉 | 一个基于 NextJS + Cloudflare 技术栈构建的可爱临时邮箱服务🎉

Full-featured mail server solution based on Postfix and Dovecot.

ChatLayout is an alternative solution to MessageKit. It uses custom UICollectionViewLayout to provide you full control over the presentation as well as all the tools available in UICollectionView. It supports dynamic cells and supplementary view sizes.

MQTT Server/MQTT Broker - Scalable Distributed MQTT Message Broker for IoT in the 5G Era

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

Distributed Application Framework for .NET

The most widely used PHP client for RabbitMQ

📤 An SMTP library for Go clients and servers

Telegram MCP server powered by Telethon to let MCP clients read chats, manage groups, and send/modify messages, media, contacts, and settings.

A curated list of awesome tips and tricks, resources, videos and articles in .NET, Software Architecture, Cloud-Native, Data and AI.

AMQP client library in Rust, with a clean, futures based API

ZapFast: a fast, native WhatsApp client in Rust and egui

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

a mailer library for Rust

:satellite: BroadcastChannel to send data between different browser-tabs or nodejs-processes :satellite: + LeaderElection over the channels https://pubkey.github.io/broadcast-channel/

🚀 Apache RocketMQ built in Rust 🦀 — faster, safer, and more memory-efficient. Powering high-performance messaging for the AI era, with AI Agent, MCP, and AI-SRE capabilities.

Eclipse Mosquitto - An open source MQTT broker

ZeroMQ core engine in C++, implements ZMTP/3.1

Real-time messaging library for Go. The simplest way to add feature-rich and scalable WebSocket support to your application. The core of Centrifugo server.

Web & desktop (Electron) client for the OCTO open workplace — one React + TypeScript codebase shipping browser and PC surfaces, with first-class AI agent UX.

Vonage Server SDK for Python. API support for Voice, SMS, WhatsApp, Verify (2FA), Video Meetings and more.

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

Kafka-style message streaming in Go. Built on NATS. Single binary, no JVM, no ZooKeeper.

Disposable webmail server (similar to Mailinator) with built in SMTP, POP3, RESTful servers; no DB required.

JavaScript plugin for finding links in plain-text and converting them to HTML <a> tags.

golang im server

:mailbox: Cross-language temporary (disposable/throwaway) email detection library. Covers 55 734+ fake email providers.

Django email backends and webhooks for Amazon SES, Brevo, MailerSend, Mailgun, Mailjet, Mailtrap, Postmark, Postal, Resend, Scaleway TEM, SendGrid, SparkPost, Unisender Go and more

Make RSS 📰 great again with AI 🧠✨!! 数据打标请联系 glidea123 (数万并发随时狂飙)

邮箱 📧 newsletter RSS 荟萃 News

:white_check_mark: A Go library for email verification without sending any emails.

A native implementation of ØMQ in Rust

TREVORspray is a modular password sprayer with threading, clever proxying, loot modules, and more!

A community-driven replacement for JSQMessagesViewController

Juice inlines CSS stylesheets into your HTML source.

A .NET MIME creation and parser library with support for S/MIME, PGP, DKIM, TNEF and Unix mbox spools.

Alpakka is a Reactive Enterprise Integration library for Java and Scala, based on Reactive Streams and Akka.

Catches mail and serves it through a dream.

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

C/C++ server and network library, including coroutine,redis client,http/https/websocket,mqtt, mysql/postgresql/sqlite client with C/C++ for Linux, Android, iOS, MacOS, Windows, Harmony,etc..

Send email in Python conveniently for gmail using yagmail

A huge list of great stuff you can get for free!

Utils library for specific Brazilian businesses

Framework for building Event-Driven Microservices

MIT-licensed PowerShell document automation for Word, Excel, PowerPoint, PDF, email, PST/OST, OneNote, Visio, OpenDocument, and mixed-format Reader workflows.

zenoh unifies data in motion, data in-use, data at rest and computations. It carefully blends traditional pub/sub with geo-distributed storages, queries and computations, while retaining a level of time and space efficiency that is well beyond any of the mainstream stacks.

A realtime distributed messaging platform

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

E-mail delivery library for Rust with DKIM support

What did I do on February 14th 2007? Visualize your (digital) life in Org-mode

Berty is a secure peer-to-peer messaging app that works with or without internet access, cellular data or trust in the network

Unofficial open source mtproto server written in golang with compatible telegram client.

RabbitMQ Bundle for the Symfony web framework

Fast and reliable message broker built on top of Kafka.

Sharding and location transparency for Scala

Modular, Production-Ready, Open-Source EHR

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

📫 A serverless email server on AWS using S3 and SES

Crossbar.io - WAMP application router

Modern email for teams and professionals. A replacement for outdated email technology and tools. Alt to hey.com, front.com, missiveapp.com

Ncurses based XMPP client

Threema App for Android.

Chatmail Rust Core library, used by Android/iOS/desktop chatmail apps, bindings and bots 📧

a list of disposable email domains

Vonage REST API client for PHP. API support for SMS, Voice, Text-to-Speech, Numbers, Verify (2FA) and more.

Ruby client for NATS, the cloud native messaging system.

Javascript and Typescript Stomp client for Web browsers and node.js apps

PingMe - A unified CLI and web service for sending notifications across multiple messaging platforms

A repository of email marketing legislation around the world, compiled by EmailOctopus.

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.

An AI agent for teams, communities, and multi-user environments.

The gold standard for async .NET microservices on Azure, AWS and on-prem

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

Franz is a free messaging app for services like WhatsApp, Slack, Messenger and many more.

A 100% native C# implementation of ZeroMQ for .NET

Notifications for Ruby on Rails applications

:bus: Simple and lean service bus implementation for .NET

JeroMQ is a pure Java implementation of the ZeroMQ messaging library, offering high-performance asynchronous messaging for distributed or concurrent applications.

:speech_balloon: Android Chat SDK ➜ Stream Chat API. UI component libraries for chat apps. Kotlin & Jetpack Compose messaging SDK for Android chat

A practical microservices with the latest technologies and architectures like Vertical Slice Architecture, Event Sourcing, CQRS, DDD, gRpc, MongoDB, RabbitMq, Wolverine, and Aspire in .Net 10.

Eclipse Hono™ Project

A Node.js library to send all kinds of transactional notifications.

Mosaico - Responsive Email Template Editor

Notification library for gophers and their furry friends.

A free and open-source email signature generator for Gmail, Outlook, Apple Mail, etc.

Multichannel notification server with support for Email, Mobile Push, Web Push, SMS, messaging and a javascript plugin.

Orchestrate end-to-end encryption, cryptographic identities, mutual authentication, and authorization policies between distributed applications – at massive scale.

Testable, composable, and adapter based Elixir email library for devs that love piping.

A simple python library to interact with Microsoft Graph and Office 365 API

A free and open-source block-based email template builder.

Kafka implemented in Golang with built-in coordination (No ZK dep, single binary install, Cloud Native)

The Official Twilio SendGrid Led, Community Driven Node.js API Library

Rapid spam filtering system.

💨 A real time messaging system to build a scalable in-app notifications, multiplayer games, chat apps in web and mobile apps.

Bunny is a popular, easy to use, mature Ruby client for RabbitMQ

A list of amazing Newsletters

An SMTP gateway for Apprise notifications.

Flutter Chat SDK - Build your own chat app experience using Dart, Flutter and the Stream Chat Messaging API.

JSON-RPC 2.0 implementation over WebSockets for Node.js and JavaScript/TypeScript

Advanced html to text converter

💬 iOS Chat SDK in Swift - Build your own app chat experience for iOS using the official Stream Chat API

Voice & Video Calling and Text Chat App for React Native

⬆ Dead simple, dependency-less, spec-compliant server-sent events implementation written in TypeScript

C API for Zenoh

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

Free email OSINT tool, 5000+ platforms, identity clustering, breach detection. No API keys required. pip install mailaccess

Python library for accurately querying username and email usage on online platforms

The Official Twilio SendGrid Python API Library

即时通讯，聊天，野火IM iOS客户端

Messaging patterns for Backbone applications.

一键自动化 下载、安装、激活 Office 的利器。

The magma server daemon, is an encrypted email system with support for SMTP, POP, IMAP, HTTP and MOLTEN,. Additional support for DMTP and DMAP is currently in active development.

Bidirectional Channels for JavaScript