Open-source email software
237 open-source libraries, tools and applications tagged email, ranked by how closely email is their primary purpose, then by adoption and maintenance health. Each entry links to a page with sources, use cases and when to choose or avoid it.
237 products, primary matches first, then adoption-weighted; health v2 shown.
| Product | Health v2 | Stars | Maturity |
|---|---|---|---|
| anymail/django-anymail A Django library providing email backends and webhook integrations for many transactional email service providers (ESPs) such as Amazon SES… | 87 | 1906 | active |
| iRedMail iRedMail is an open source, full-featured mail server solution that installs and configures SMTP, IMAP/POP3, webmail (Roundcube/SOGo), and … | 77 | 1848 | active |
| mailvelope/mailvelope Mailvelope is a browser extension for Chrome and Firefox that adds OpenPGP end-to-end email encryption to arbitrary webmail providers. It u… | 85 | 1847 | active |
| Magma Encrypted Email System Magma is an encrypted email server daemon written in C, providing SMTP, POP, IMAP, and HTTP protocol support along with a bundled webmail s… | 33 | 1831 | active |
| mozilla/fx-private-relay Firefox Relay is a Mozilla service that generates email aliases (masks) which forward messages to your real inbox, hiding your personal add… | 95 | 1802 | active |
| fphilipe/premailer-rails A Ruby gem that automatically inlines CSS into HTML emails by converting linked stylesheets and style tags into inline style attributes. It… | 32 | 1767 | stable |
| cypht-org/cypht Cypht is a lightweight open-source webmail aggregator that combines multiple email accounts (IMAP/SMTP, JMAP, and EWS) into a single unifie… | 96 | 1765 | active |
| html-to-text/node-html-to-text A Node.js monorepo providing an advanced HTML to plain text converter, available as a library (html-to-text) and a CLI (@html-to/text-cli),… | 73 | 1762 | active |
| usewaypoint/email-builder-js EmailBuilder.js is a free, open-source, block-based email template builder for developers that outputs clean JSON or HTML rendering well ac… | 52 | 1761 | active |
| un/inbox UnInbox is an open-source collaborative email platform for teams and professionals, offering shared inboxes, unlimited addresses, conversat… | 56 | 1755 | active |
| arithmetric/aws-lambda-ses-forwarder A Node.js script for AWS Lambda that uses AWS Simple Email Service (SES) inbound/outbound capabilities to run a serverless email forwarding… | 23 | 1729 | stable |
| djcb/mu mu is a set of command-line tools for indexing and searching email stored in the Maildir format on Unix-like systems. It also includes mu4e… | 92 | 1718 | active |
| joeyates/imap-backup imap-backup is a Ruby command-line tool for backing up and migrating IMAP email accounts. It downloads messages to local storage and can re… | 72 | 1717 | active |
| barbushin/php-imap A PHP library for connecting to mailboxes via POP3, IMAP, and NNTP using the PHP IMAP extension. It enables fetching, filtering, sorting, m… | 79 | 1699 | active |
| Forward Email Forward Email is a 100% open-source, privacy-focused email service providing free email forwarding for custom domains, plus outbound SMTP, … | 95 | 1686 | active |
| vladimiry/ElectronMail ElectronMail is an unofficial Electron-based desktop client for ProtonMail, written in TypeScript with Angular. It provides an enhanced des… | 93 | 1680 | active |
| spatie/laravel-newsletter A Laravel package providing a simple API to manage newsletter subscriptions across email services like Mailcoach, Mailchimp, and MailerLite… | 78 | 1640 | active |
| AfterShip/email-verifier A Go library for verifying email addresses without sending any emails. It validates syntax, checks DNS MX records, performs SMTP verificati… | 84 | 1633 | active |
| SendGrid Python API Library Official Twilio SendGrid API client libraries for sending email and calling the SendGrid Web API v3, maintained as multi-language monorepos… | 71 | 1629 | active |
| mlandauer/cuttlefish Cuttlefish is a self-hosted transactional email server built on Postfix with a Ruby on Rails web interface. It lets applications send email… | 32 | 1623 | active |
| Proton Mail Proton Mail's official iOS client for end-to-end encrypted email, written in Swift/SwiftUI with core business logic in a Rust-based SDK. Th… | 63 | 1620 | active |
| idinging/freemail Freemail is an open-source temporary/disposable email service built on Cloudflare Workers, D1, and R2, with a separated frontend and backen… | 74 | 1619 | active |
| Maizzle Maizzle is a framework for building production-ready HTML emails using Vue single-file components and Tailwind CSS. It provides a modern de… | 100 | 1618 | active |
| bkaankose/Wino-Mail Wino Mail is a native Windows mail and calendar client that recreates the look and feel of the deprecated built-in Windows Mail & Calendar … | 98 | 1597 | active |
| symfony/mailer Symfony Mailer is a PHP component for creating and sending emails via SMTP or third-party transports. It supports multipart messages, attac… | 96 | 1596 | stable |
| labnol/unsubscribe-gmail Gmail Unsubscriber is an open-source Google Apps Script that automatically unsubscribes your email address from unwanted newsletters and bu… | 35 | 1569 | active |
| ProtonMail/proton-bridge Proton Mail Bridge is a desktop application that runs local IMAP and SMTP servers, allowing standard email clients to send and receive encr… | 95 | 1554 | active |
| antonreshetov/mysigmail MySigMail is a free, open-source email signature generator built with Vue that creates professional HTML signatures for Gmail, Outlook, App… | 58 | 1552 | active |
| swoosh/swoosh Swoosh is an Elixir library for composing, delivering, and testing emails. It provides a unified mailer API with adapters for popular provi… | 97 | 1527 | active |
| mailslurper/mailslurper MailSlurper is a lightweight, web-based SMTP mail server written in Go that captures emails sent by applications during development. It sto… | 44 | 1512 | active |
| wneessen/go-mail go-mail is a modern, feature-rich Go library for composing and sending email over SMTP. It provides mail composition, encoding, DKIM and S/… | 89 | 1497 | active |
| oiov/vmail Vmail is a self-hosted temporary/disposable email service built entirely on Cloudflare Workers and D1, deployable with just a domain. It su… | 73 | 1487 | active |
| simonrob/email-oauth2-proxy A local IMAP/POP/SMTP proxy written in Python that transparently adds OAuth 2.0 authentication for email clients that don't support it. It … | 78 | 1473 | active |
| JoshData/python-email-validator A Python library that validates email address syntax and optionally checks domain deliverability via DNS. It normalizes addresses, supports… | 68 | 1450 | stable |
| Oxygem/Kanmail Kanmail is a desktop email client that presents your inbox as a kanban board, with emails as draggable cards and folders/labels as columns.… | 93 | 1381 | active |
| anypost/emailmd emailmd is a TypeScript library and CLI that converts markdown into responsive, email-safe HTML (via MJML) that renders correctly across Gm… | 82 | 1380 | active |
| emalderson/ThePhish ThePhish is an automated phishing email analysis web application built on TheHive, Cortex, and MISP. It extracts observables from email hea… | 32 | 1377 | stable |
| jetmore/swaks Swaks is a scriptable, transaction-oriented SMTP test tool written in Perl, often called the Swiss Army Knife for SMTP. It supports SMTP, E… | 23 | 1347 | active |
| go-gomail/gomail Gomail is a Go library for sending emails via SMTP with a simple, flexible API. It supports attachments, embedded images, HTML/text templat… | 32 | 4732 | maintenance |
| snowfire/Beautymail A Laravel package for sending beautiful, responsive HTML emails using pre-built templates like Widgets, Minty, and Sunny. It integrates wit… | 24 | 1315 | active |
| domainaware/parsedmarc parsedmarc is a Python module and CLI utility for parsing aggregate (rua), failure (ruf), and SMTP TLS reporting email authentication repor… | 94 | 1306 | active |
| bbottema/simple-java-mail Simple Java Mail is a Java library that wraps Jakarta Mail with a fluent builder API for composing and sending well-formed MIME emails. It … | 97 | 1292 | stable |
| microsoft/CSS-Exchange A collection of PowerShell scripts from Microsoft Customer Service and Support for diagnosing and fixing issues in Microsoft Exchange Serve… | 92 | 1284 | active |
| Truemail Truemail is a configurable, framework-agnostic plain Ruby gem for validating and verifying email addresses. It validates emails via regex, … | 23 | 1282 | stable |
| ecederstrand/exchangelib A Python client library for Microsoft Exchange Web Services (EWS) that provides a Django-style ORM interface to Exchange mailboxes. It supp… | 63 | 1273 | active |
| Dovecot Dovecot is an open-source mail server for Linux/UNIX-like systems written in C, providing IMAP, POP3, LMTP, and ManageSieve protocols with … | 88 | 1266 | stable |
| shellscape/jsx-email JSX email is a TypeScript library and CLI for building responsive, standards-compliant email templates using JSX/TSX components. It include… | 71 | 1262 | active |
| Bulwark Webmail Bulwark Webmail is a self-hosted webmail client built with Next.js and TypeScript that speaks the JMAP protocol and is designed specificall… | 81 | 1259 | active |
| PostfixAdmin PostfixAdmin is an open-source, web-based administration interface for managing domains, mailboxes, and aliases on Postfix-based mail serve… | 93 | 1257 | active |
| technomancy-dev/00 00 is a self-hostable dashboard and microservice for sending and monitoring transactional emails via AWS SES. It automates the SES -> SNS -… | 25 | 1244 | active |
| SparkPost/heml HEML is an open source XML-based markup language and framework for building responsive HTML emails, developed by SparkPost. It compiles HEM… | 23 | 4293 | maintenance |
| marcboeker/gmail-to-sqlite A Python CLI application that syncs Gmail messages into a local SQLite database, supporting incremental and full syncs with deletion detect… | 71 | 1223 | active |
| bootstrap-email/bootstrap-email Bootstrap Email is a stylesheet, compiler, and CSS inliner that lets you write HTML emails using Bootstrap-like syntax and compiles it into… | 61 | 1219 | active |
| AllAboutAI-YT/easy-local-rag A Python application providing 100% local retrieval-augmented generation (RAG) using Ollama for LLM inference and embeddings. It supports i… | 16 | 1219 | active |
| martinrusev/imbox Imbox is a Python library and CLI for reading IMAP mailboxes and converting email content into machine-readable JSON data. It is designed f… | 69 | 1217 | active |
| ankane/ahoy_email Ahoy Email is a Ruby gem providing first-party email analytics for Rails applications. It offers message history storage, UTM link tagging,… | 75 | 1195 | active |
| email-spec/email-spec A Ruby library providing RSpec/MiniTest matchers and Cucumber/Spinach steps for testing email delivery in applications using ActionMailer o… | 62 | 1187 | active |
| RainLoop/rainloop-webmail RainLoop Webmail is a simple, modern, and fast web-based email client written in PHP that connects directly to mail servers via IMAP and SM… | 10 | 4115 | maintenance |
| GongRzhe/Gmail-MCP-Server A Model Context Protocol (MCP) server that integrates Gmail with AI assistants like Claude Desktop, featuring automatic OAuth2 authenticati… | 10 | 1168 | active |
| mailgun/mailgun-php The official Mailgun SDK for PHP, a PSR-18 HTTP client wrapper around the Mailgun email API. It lets PHP applications send, track, and mana… | 90 | 1136 | active |
| floatpane/matcha Matcha is a terminal-based email client built in Go using the Bubble Tea TUI framework, offering a modern interface for reading, managing, … | 81 | 1127 | active |
| MailTrackerBlocker MailTrackerBlocker is a mail bundle plugin and extension for Apple Mail on macOS that strips email trackers, read receipts, and spy pixels … | 73 | 1123 | active |
| freeCodeCamp/mail-for-good Mail for Good is an open-source, self-hosted email campaign management application built for nonprofits. It sends bulk email campaigns via … | 10 | 3809 | maintenance |
| ui/django-post_office Django Post Office is a Django app for sending and managing email asynchronously, with support for HTML email, database-backed and multilin… | 90 | 1096 | active |
| django-ses/django-ses django-ses is a drop-in Django email backend that sends mail through Amazon's Simple Email Service (SES) instead of SMTP, and can also rece… | 94 | 1090 | active |
| rpgp/rpgp rPGP is a pure Rust implementation of OpenPGP (RFC9580, RFC4880, RFC6637) with a flexible low-level API, published as the `pgp` crate. It s… | 88 | 1078 | active |
| N0rz3/Zehef Zehef is a Python command-line OSINT tool for investigating email addresses. It checks for pastes, data leaks, and linked social media acco… | 30 | 1075 | active |
| amro/gibbon Gibbon is a Ruby gem that wraps MailChimp's Marketing API, exposing its resources through chainable request objects with CRUD verbs. It ret… | 71 | 1065 | active |
| gaubert/gmvault Gmvault is a Python command-line tool for backing up and restoring Gmail accounts, storing emails locally with incremental sync support. It… | 32 | 3640 | maintenance |
| kurrier-org/kurrier Kurrier is a self-hosted, open-source workspace that unifies email, calendars, contacts, and file storage into a single modern web interfac… | 80 | 1059 | active |
| apache/james-project Apache James is an enterprise mail server and modular mail platform running on the JVM, supporting SMTP, IMAP, POP3, JMAP, LMTP, and Manage… | 76 | 1048 | stable |
| nextcloud/mail Nextcloud Mail is a webmail client app for Nextcloud that connects to any IMAP/SMTP account, built on the Horde PHP libraries with a Vue si… | 68 | 1038 | active |
| zoidsh/meru Meru (formerly Gmail Desktop) is an open-source Electron-based desktop app that wraps Gmail for macOS, Windows, and Linux. It supports mult… | 94 | 1035 | active |
| sabuhish/fastapi-mail Fastapi-mail is a lightweight Python library for sending emails from FastAPI applications, supporting individual and bulk messages, attachm… | 93 | 1013 | active |
| soheilpro/mailwind A command-line tool that lets you design HTML emails using Tailwind CSS utility classes and compiles them into email-ready CSS or HTML with… | 32 | 3185 | maintenance |
| leemunroe/grunt-email-workflow A Grunt-based build workflow for designing and testing responsive HTML email templates using SCSS. It compiles SCSS to CSS, builds HTML ema… | 32 | 3034 | maintenance |
| flashmob/go-guerrilla Go-Guerrilla is a lightweight SMTP server daemon written in Go, designed for receiving large volumes of email quickly and efficiently. It c… | 23 | 2964 | maintenance |
| jordan-wright/email A Go library for composing and sending email over SMTP with a simple, human-friendly API. It supports text and HTML bodies, attachments, cu… | 23 | 2791 | maintenance |
| MailCore/mailcore2 MailCore 2 is a C++/Objective-C library providing a simple, asynchronous API for working with email protocols IMAP, POP, and SMTP. It inclu… | 67 | 2698 | maintenance |
| sensepost/ruler Ruler is a Go-based command-line tool for interacting with and abusing Microsoft Exchange servers via MAPI/HTTP or RPC/HTTP. It enables off… | 23 | 2310 | maintenance |
| mscdex/node-imap node-imap is an IMAP client module for Node.js that lets applications connect to IMAP mail servers, list mailboxes, and fetch messages and … | 32 | 2221 | maintenance |
| emersion/hydroxide Hydroxide is a third-party, open-source ProtonMail bridge written in Go that translates standard protocols (IMAP, SMTP, CardDAV) into Proto… | 10 | 2169 | maintenance |
| drewm/mailchimp-api A super-simple, minimal-abstraction PHP wrapper for the MailChimp API v3. It maps API endpoints directly to simple get/post/patch/delete ca… | 23 | 1974 | maintenance |
| Flolagale/mailin Mailin is an SMTP server that receives inbound emails, parses them, and posts them as JSON to a webhook URL of your choice. It also validat… | 23 | 1954 | maintenance |
| OfflineIMAP/offlineimap OfflineIMAP is a Python command-line tool that synchronizes IMAP mailboxes to local Maildir folders, enabling offline email reading and ind… | 23 | 1860 | maintenance |
| voidlabs/mosaico Mosaico is an open-source JavaScript library/single-page application for visually editing responsive email templates via drag and drop. Edi… | 66 | 1783 | maintenance |
| chenjj/espoofer espoofer is a Python-based testing tool that crafts spoofed emails to bypass SPF, DKIM, and DMARC authentication, including forged DKIM sig… | 32 | 1755 | maintenance |
| nodemailer/mailparser An advanced email parser for Node.js that decodes MIME-formatted emails, handling everything as streams to parse very large messages with l… | 96 | 1670 | maintenance |
| g13nn/Email-Framework A responsive HTML email framework providing boilerplates, grid systems, components, and snippets for building HTML email templates. It supp… | 32 | 1668 | maintenance |
| mailgun/flanker Flanker is a Python library by Mailgun for parsing email addresses and MIME messages. It provides robust address parsing (single addresses … | 64 | 1647 | maintenance |
| leggett/simplify Issue tracker repository for Simplify Gmail, a browser extension that simplifies and enhances Gmail's interface. The extension itself is no… | 32 | 1636 | maintenance |
| Cloudflare Email Sending A Cloudflare Workers-based proxy server for sending free transactional emails via the MailChannels API. It exposes an authenticated HTTP en… | 51 | 1600 | maintenance |
| denghongcai/forsaken-mail Forsaken Mail is a self-hosted disposable email service that lets you receive emails at temporary addresses via a built-in SMTP server and … | 32 | 1552 | maintenance |
| Raikia/FiercePhish FiercePhish is a self-hosted PHP web application for managing full phishing engagements, including campaign tracking, scheduled email sendi… | 23 | 1437 | maintenance |
| Roadie A Ruby gem that makes HTML emails easier by inlining stylesheets into the markup and rewriting relative URLs to absolute ones. It handles e… | 76 | 1349 | maintenance |
| Talon Talon is a Python library from Mailgun that extracts reply quotations and signatures from email messages, both plain text and HTML. It comb… | 100 | 1346 | maintenance |
| Resend Email Platform React Email is a collection of high‑quality, unstyled React components for building email templates. It lets developers write emails using … | 80 | 399 | active |
| beyondcode/laravel-mailbox A Laravel package that lets applications catch and react to incoming emails from services like Mailgun, SendGrid, and Postmark, or a local … | 65 | 1135 | maintenance |
| Hedwig Hedwig is a Swift package providing high-level APIs for sending email through any SMTP server, supporting plain, SSL, and STARTTLS connecti… | 53 | 1123 | maintenance |
| peterbe/premailer A Python library that transforms HTML email markup by converting <style> blocks and external stylesheets into inline style attributes on ea… | 32 | 1082 | maintenance |