Ross ROSS = Recommend OSS · open-source software intelligence for agents

domain: email

235 products, primary matches first, then adoption-weighted; health v2 shown.

ProductHealth v2StarsMaturity
adam-p/markdown-here
Markdown Here is a browser and email-client extension (Chrome, Firefox, Opera, Safari, Thunderbird, Postbox) that lets users write email in…
5160247active
knadh/listmonk
listmonk is a self-hosted, high-performance newsletter and one-way mailing list manager written in Go, packaged as a single binary with a V…
9223140stable
PHPMailer/PHPMailer
PHPMailer is a full-featured PHP library for creating and sending email, with integrated SMTP support, authentication, attachments, HTML/mu…
8922280stable
resend/react-email
React Email is a collection of high-quality, unstyled React components for building responsive email templates with TypeScript, handling em…
9519669active
docker-mailserver/docker-mailserver
A production-ready, containerized fullstack mail server bundling Postfix (SMTP), Dovecot (IMAP/POP3), Rspamd, SpamAssassin, ClamAV, Fail2ba…
7918803active
mjmlio/mjml
MJML is a markup language and open-source engine that compiles semantic, component-based markup into responsive HTML email that renders rel…
9618211stable
Foundry376/Mailspring
Mailspring is a fully open source desktop email client for Mac, Windows, and Linux, built with Electron, React, and TypeScript, with a C++ …
9717761active
nodemailer/nodemailer
Nodemailer is the most popular email sending library for Node.js, supporting SMTP, Sendmail, Amazon SES, and custom transports. It handles …
9717659stable
Billionmail/BillionMail
BillionMail is a self-hosted, open-source mail server and email marketing platform built on Postfix, Dovecot, and Rspamd, with campaign man…
6815456active
mail-in-a-box/mailinabox
Mail-in-a-Box is a one-click, easy-to-deploy mail server appliance that turns a fresh Ubuntu 22.04 machine into a complete email provider w…
9015396active
stalwartlabs/stalwart
Stalwart is an open-source, all-in-one mail and collaboration server written in Rust, supporting JMAP, IMAP4, POP3, SMTP, CalDAV, CardDAV a…
9714362active
thunderbird/thunderbird-android
Thunderbird for Android is a free, open-source, privacy-focused email client for Android, formerly known as K-9 Mail and now part of the Mo…
9813923active
maillab/cloud-mail
Cloud Mail is a self-hosted email service built on Cloudflare Workers that lets you create and manage multiple mailboxes using just a domai…
8613710active
mailcow/mailcow-dockerized
mailcow: dockerized is a full-featured, self-hosted mail server suite delivered as a set of Docker containers, bundling Postfix, Dovecot, S…
9813330stable
elie222/inbox-zero
Inbox Zero is an open-source AI email assistant web application that organizes your inbox, pre-drafts replies in your voice, blocks cold em…
9612091active
egulias/EmailValidator
A PHP library for validating email addresses against multiple RFC standards (5321, 5322, 6530-6532, 1035). It offers pluggable validation s…
3511641stable
dreamhunter2333/cloudflare_temp_email
A self-hosted temporary/disposable email service built entirely on Cloudflare's free tier (Workers, Pages, Email Routing). It provides a mo…
9511557active
Mail-0/Zero
Zero (Mail0) is an open-source, self-hostable email client that unifies multiple providers like Gmail and Outlook into one privacy-first in…
4910784active
axllent/mailpit
Mailpit is a lightweight, zero-dependency email and SMTP testing tool for developers that acts as a local SMTP server and captures outgoing…
9410209active
reacherhq/check-if-email-exists
A Rust library and CLI that checks whether an email address exists via SMTP/MX lookups without sending an actual email. It also ships as a …
769485active
openclaw/gogcli
gog is a single Go binary CLI that provides terminal access to Google Workspace services including Gmail, Calendar, Drive, Docs, Sheets, Sl…
838330active
tutao/tutanota
Tuta Mail (formerly Tutanota) is an open-source, end-to-end encrypted email service with integrated encrypted calendar and contacts, availa…
957874active
Mailu/Mailu
Mailu is a full-featured, self-hosted email server distributed as a set of Docker images, providing SMTP, IMAP, webmail, and an admin inter…
987474active
roundcube/roundcubemail
Roundcube Webmail is a browser-based, multilingual IMAP email client written in PHP with an application-like user interface. It offers full…
987131stable
pimalaya/himalaya
Himalaya is a command-line email client written in Rust for listing, reading, composing, sending, searching, and moving messages. It suppor…
907112active
cloudflare/agentic-inbox
A self-hosted email client with an integrated AI agent that runs entirely on Cloudflare Workers. Incoming mail is handled via Cloudflare Em…
496998active
simple-login/app
SimpleLogin is an open-source email aliasing service that lets users create unique aliases to receive and send emails without exposing thei…
946950active
jstedfast/MailKit
MailKit is a cross-platform .NET mail client library built on top of MimeKit, providing IMAP, POP3, and SMTP support along with a high-perf…
766844stable
sj26/mailcatcher
MailCatcher is a Ruby gem that runs a lightweight fake SMTP server which catches all outgoing mail from an application and displays it in a…
676778stable
foxcpp/maddy
Maddy is a composable all-in-one mail server written in Go that combines an SMTP MTA/MX, IMAP storage, and email security protocols (DKIM, …
926077active
maildev/maildev
MailDev is a local SMTP server with a modern web interface that catches all emails sent by your application during development, so nothing …
866032active
openpgpjs/openpgpjs
OpenPGP.js is a pure JavaScript implementation of the OpenPGP protocol (RFC 9580), maintained by Proton Mail. It lets applications encrypt,…
905969stable
mjl-/mox
Mox is an all-in-one, secure, open source mail server written in Go, combining SMTP, IMAP4, webmail, SPF/DKIM/DMARC, DANE/MTA-STS, automati…
935826active
tijsverkoyen/CssToInlineStyles
A PHP library that converts HTML pages or files by inlining their CSS styles directly into the HTML elements. This is primarily useful for …
575826stable
Mailtrain-org/mailtrain
Mailtrain is a self-hosted newsletter application built on Node.js and MySQL/MariaDB for managing subscriber lists and sending email campai…
435748active
haraka/Haraka
Haraka is a fast, highly extensible, event-driven SMTP server written in Node.js with a modular plugin architecture. It is widely deployed …
935613stable
ProtonMail/WebClients
The official monorepo for Proton's web clients, including Proton Mail, Calendar, Drive, VPN, Pass, Wallet, and more. It is built with React…
845562active
useplunk/plunk
Plunk is an open-source, self-hostable email platform combining transactional email sending (API and SMTP), marketing campaigns, and event-…
905396active
unlayer/react-email-editor
An official React component that embeds Unlayer's drag-and-drop email editor into any React application. It lets developers load and save e…
945208active
anonaddy/anonaddy
The self-hostable source code for addy.io (formerly AnonAddy), an open-source anonymous email forwarding service. It lets users create emai…
964818active
usesend/useSend
useSend is an open-source, self-hostable email sending platform built on Amazon SES, offering transactional and marketing email delivery wi…
884640active
M66B/FairEmail
FairEmail is a fully featured, open source, privacy oriented email client for Android. It supports unlimited accounts via standard protocol…
954582active
sdushantha/tmpmail
tmpmail is a command line utility written in POSIX sh that creates temporary/disposable email addresses and receives emails via the 1secmai…
234188stable
imapsync/imapsync
Imapsync is a command-line tool written in Perl that performs incremental, recursive, duplicate-free transfers between two IMAP mailboxes. …
754130active
arikchakma/maily.to
Maily is a powerful, opinionated WYSIWYG email editor built on Tiptap and React, offering pre-designed, mobile-ready components for craftin…
713949active
rnwood/smtp4dev
smtp4dev is a fake SMTP email server for development and testing, with a web interface, terminal UI, and REST API. It captures outgoing mai…
903945active
KartikTalwar/gmail.js
Gmail.js is a JavaScript library that provides an unofficial API for interacting with Gmail's web interface from browser extensions. It let…
753842active
ryanb/letter_opener
A Ruby gem that intercepts outgoing email in development and previews it in the browser instead of sending it. It integrates with Rails Act…
683842stable
neomutt/neomutt
NeoMutt is a highly configurable, terminal-based command line email reader (MUA) forked from Mutt, written in C. It consolidates many commu…
913817active
mailhog/MailHog
MailHog is an email testing tool that runs a fake SMTP server and exposes a web UI and JSON API for inspecting outgoing messages. It can op…
2316138maintenance
forwardemail/email-templates
A Node.js library for creating, previewing, and sending custom email templates with automatic CSS inlining. It integrates with Nodemailer a…
613739active
mikel/mail
Mail is a pure Ruby library for generating, parsing, and sending/receiving email messages in a simple, Ruby-esque way. It proxies network a…
813671stable
sofn-xyz/mailing
Mailing is an open-source TypeScript tool for building, testing, and sending emails using React components and MJML. It includes a hot-relo…
733602active
modoboa/modoboa
Modoboa is an open-source mail hosting and management platform with a modern web UI, built in Python/Django and Vue. It integrates Postfix,…
983532stable
ChangemakerStudios/Papercut-SMTP
Papercut SMTP is a desktop application that runs a local SMTP server and displays every email your application sends, so nothing is ever de…
993325active
Automattic/juice
Juice is a JavaScript library and CLI that inlines CSS stylesheets into HTML by converting CSS rules into style attributes. It is primarily…
983278active
dafthack/MailSniper
MailSniper is a PowerShell-based penetration testing tool for searching email in Microsoft Exchange environments for sensitive terms like p…
773276active
lukencode/FluentEmail
FluentEmail is an all-in-one email sending library for .NET and .NET Core with a fluent API. It supports multiple senders (SMTP, SendGrid, …
323215stable
GAM-team/got-your-back
Got Your Back (GYB) is a Python command line tool that backs up and restores Gmail messages to your local computer using Gmail's API over H…
773103active
leafac/kill-the-newsletter
A self-hostable web application that converts email newsletters into Atom feeds. It gives each feed a unique email address; incoming newsle…
743087active
matcornic/hermes
Hermes is a Go package that generates clean, responsive HTML emails for transactional mail such as welcome, password-reset, and receipt ema…
293024active
dittofeed/dittofeed
Dittofeed is an open-source, omni-channel customer engagement platform for sending transactional and marketing messages via email, SMS, mob…
742914active
zalify/easy-email-editor
Easy Email Editor is an open-source React component library for building drag-and-drop email editors that generate responsive HTML via MJML…
762911active
charmbracelet/pop
Pop is a terminal-based tool for sending emails, offering both an interactive TUI and a CLI for piping Markdown messages with attachments. …
952901active
symfony/mime
Symfony MIME is a PHP component for creating and manipulating MIME messages, including email construction with headers, attachments, and mu…
952827stable
beilunyang/moemail
MoeMail is a self-hostable temporary (disposable) email service with a cute web UI, built on Next.js and the Cloudflare stack (Pages, Worke…
832799active
kootenpv/yagmail
yagmail is a Python library that makes sending emails via Gmail/SMTP as simple as a single client call, with 'magical' handling of text, HT…
702734active
LukeSmithxyz/mutt-wizard
mutt-wizard is a shell-based tool that automatically configures the neomutt terminal email client along with isync and msmtp, including IMA…
652639active
eladnava/mailgen
A Node.js package that programmatically generates clean, responsive HTML emails for transactional mail, with bundled themes and plaintext o…
752542stable
rspamd/rspamd
Rspamd is an advanced spam filtering system and email processing framework written in C with an extensive Lua plugin API. It evaluates mess…
992514active
premailer/premailer
Premailer is a Ruby gem that prepares HTML email for delivery by inlining CSS styles, converting relative URLs to absolute, and checking CS…
762416active
emersion/go-imap
go-imap is an IMAP4rev2 protocol library for Go, providing both client and server implementations. It lets Go applications talk to mail ser…
762350active
SendWithSES/Drag-and-Drop-Email-Designer
An open-source Angular library providing a drag-and-drop HTML email template designer with no-code editing, HTML code editing, and plain te…
652302active
LogicLabs-OU/OpenArchiver
OpenArchiver is an open-source, self-hosted platform for legally compliant email archiving and eDiscovery. It ingests email from Google Wor…
852281active
inbucket/inbucket
Inbucket is a self-hosted disposable webmail (email testing) server that accepts messages for any address via built-in SMTP and exposes the…
642263stable
mailpile/Mailpile
Mailpile is a free, open-source, privacy-focused email client with built-in PGP encryption, a fast custom search engine, and tag-based orga…
238822maintenance
lettre/lettre
lettre is a mailer library for Rust that lets applications compose and send emails via SMTP, sendmail, and other transports. It offers a st…
922255stable
postalsys/emailengine
EmailEngine is a self-hosted, source-available (not open-source) headless email client that exposes IMAP, SMTP, Gmail API, and Microsoft Gr…
952217active
eleith/emailjs
emailjs is a TypeScript library for sending text and HTML emails with attachments (files, streams, or strings) to any SMTP server from Node…
772211active
langchain-ai/executive-ai-assistant
Executive AI Assistant (EAIA) is an open-source AI agent built with LangGraph that performs the job of an executive assistant, primarily by…
102208active
pentacent/keila
Keila is an open source (AGPL-3.0) email newsletter tool written in Elixir, positioned as an alternative to Mailchimp or Sendinblue. It sup…
912192active
mbrt/gmailctl
gmailctl is a Go CLI tool that lets you manage Gmail filters declaratively using Jsonnet configuration files. It applies filters directly t…
812192active
LukeSmithxyz/emailwiz
A shell script that automates installing and configuring a full email server on Debian/Ubuntu using Postfix, Dovecot, Spamassassin, OpenDKI…
412166active
mettle/sendportal
SendPortal is an open-source, self-hosted email marketing application for managing newsletters, subscribers, and campaigns. It is a Laravel…
232160active
Alinto/sogo
SOGo is an open-source groupware (collaboration) server offering webmail, shared calendars, address books, and tasks. It uses open standard…
942153stable
zone-eu/wildduck
WildDuck is a scalable, no-single-point-of-failure IMAP/POP3 email server built on Node.js that stores all mail in sharded and replicated M…
992109active
Qoraiche/laravel-mail-editor
MailEclipse is a Laravel package that provides a web UI for creating, editing, and previewing mailables without using the command line. It …
362106active
Notifuse/notifuse
Notifuse is an open-source, self-hosted email marketing and transactional email platform built with Go and React. It offers a visual MJML d…
822077active
s1t5/mail-archiver
Mail-Archiver is a self-hosted web application for archiving, searching, and exporting emails from multiple accounts (IMAP, Microsoft 365, …
852076active
Gururagavendra/gmail-cleaner
A free, open-source, self-hosted web application for bulk cleaning of Gmail inboxes. It runs locally via Docker or Python and uses the Gmai…
702074active
mailcheck/mailcheck
A JavaScript library and jQuery plugin that detects misspelled email domains and suggests corrections, e.g. turning '[email protected]' into 'u…
237938maintenance
Jinnrry/PMail
PMail is a lightweight personal email server written in Go that ships as a single ~15MB binary with full send/receive SMTP/POP3 services an…
942045active
emersion/go-smtp
An ESMTP client and server library for Go implementing RFC 5321 with extensions like AUTH, PIPELINING, and LMTP. It improves on the frozen …
942042active
foundation/foundation-emails
Foundation for Emails (formerly Ink) is an HTML/CSS framework for building responsive HTML emails that render consistently across email cli…
787791maintenance
jstedfast/MimeKit
MimeKit is a C#/.NET library for creating and parsing MIME email messages, with support for S/MIME, OpenPGP, DKIM, ARC, TNEF, and Unix mbox…
762000stable
beam-community/bamboo
Bamboo is an adapter-based email library for Elixir that separates email creation from delivery, with built-in adapters for services like M…
701959stable
rustmailer/bichon
Bichon is a self-hosted email archiving server written in Rust that downloads emails from IMAP accounts, builds a full-text search index, a…
831931active
O365/python-o365
A Python library providing a Pythonic wrapper around the Microsoft Graph and Office 365 REST APIs. It supports email, calendar, contacts, O…
551923active
ZeroPointSix/outlookEmailPlus
OutlookMail Plus is a self-hosted email manager purpose-built for account registration and verification workflows. It automates fetching ve…
811917active
FGRibreau/mailchecker
MailChecker is a cross-language library for validating email format and detecting temporary/disposable email addresses, backed by a databas…
771905active

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