1.maillab / cloud-mail
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
+283 stars
from 14,950 · score 5.65
Trending repositories
Ranked by Attention Score: stars gained over the last 7 complete days
49 repositories by Attention Score · Oct 27, 2026 – Nov 2, 2026 (UTC)
2.Billionmail / BillionMail
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
+193 stars
from 15,953 · score 5.27
3.marclou / mailcheap
Newsletters where you pay for the emails you send, not for dormant subscribers, at a fraction of the price of beehiiv and the like. Open source: self-host it, or use mailcheap.ai.
+148 stars
from 1,448 · score 5.00
4.flectar / mail
Built from the ground up for speed. Flectar Mail delivers native performance, instant startup, and as little as 80 MB of RAM.
+109 stars
from 1,616 · score 4.70
5.megadose / holehe
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.
+107 stars
from 15,382 · score 4.68
6.mailschema / mailschema
Working-draft Mail Action Protocol for agent actions through email, with type contracts, a registry, and a validation CLI.
+80 stars
from 116 · score 4.39
7.elie222 / inbox-zero
The world's best AI personal assistant for email. Open source app to help you reach inbox zero fast.
+71 stars
from 12,809 · score 4.28
8.logto-io / logto
🧑🚀 Authentication and authorization infrastructure for SaaS and AI apps, built on OIDC and OAuth 2.1 with multi-tenancy, SSO, and RBAC.
+47 stars
from 14,784 · score 3.87
9.tutao / tutanota
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.
+47 stars
from 8,046 · score 3.87
10.frappe / frappe
Low code web framework for real world applications, in Python and Javascript
+46 stars
from 10,997 · score 3.85
11.Foundry376 / Mailspring
:love_letter: A beautiful, fast and fully open source mail client for Mac, Windows and Linux.
+45 stars
from 17,942 · score 3.83
12.OdysseusYuan / LKY_OfficeTools
一键自动化 下载、安装、激活 Office 的利器。
+44 stars
from 12,929 · score 3.81
13.novuhq / novu
The open-source communication infrastructure for agents and products
+43 stars
from 40,204 · score 3.78
14.thunderbird / thunderbird-android
Thunderbird for Android – Open Source Email App for Android (fka K-9 Mail)
+32 stars
from 14,138 · score 3.50
15.dreamhunter2333 / cloudflare_temp_email
CloudFlare free temp domain email 免费收发 临时域名邮箱 支持附件 IMAP SMTP TelegramBot
+27 stars
from 12,019 · score 3.33
16.resend / react-email
💌 Build and send emails using React
+24 stars
from 19,876 · score 3.22
17.simple-login / app
The SimpleLogin back-end and web app
+24 stars
from 7,086 · score 3.22
18.rustmailer / bichon
Bichon – A lightweight, high-performance Rust email archiver with WebUI
+15 stars
from 2,047 · score 2.77
19.dittofeed / dittofeed
Open-source customer engagement. Automate transactional and marketing messages across email, SMS, mobile push, WhatsApp, Slack, and more 📨
+14 stars
from 3,023 · score 2.71
20.EvotecIT / OfficeIMO
MIT-licensed, COM-free .NET libraries for creating, reading, editing, converting, rendering, and extracting Office, PDF, email, OneNote, and text formats.
+13 stars
from 636 · score 2.64
21.Mail-0 / Zero
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
+11 stars
from 10,861 · score 2.48
+11 stars
from 4,922 · score 2.48
23.PHPMailer / PHPMailer
The classic email sending library for PHP
+10 stars
from 22,332 · score 2.40
24.nodemailer / nodemailer
✉️ Send e-mails with Node.JS – easy as cake!
+9 stars
from 17,692 · score 2.30
25.forwardemail / forwardemail.net
Privacy-focused encrypted email for everyone. All-in-one alternative to Gmail + Mailchimp + Sendgrid.
+8 stars
from 1,691 · score 2.20
26.jstedfast / MailKit
A cross-platform .NET library for IMAP, POP3, and SMTP.
+7 stars
from 6,863 · score 2.08
27.jonathandion / awesome-emails
✉️ An awesome list of resources to build better emails.
+6 stars
from 2,763 · score 1.95
28.wneessen / go-mail
📧 Easy to use, yet comprehensive library for sending mails with Go
+6 stars
from 1,503 · score 1.95
29.onetimesecret / onetimesecret
Keep passwords and other sensitive information out of your chat logs and inboxes.
+5 stars
from 2,971 · score 1.79
30.Mailu / Mailu
Insular email distribution - mail server as Docker images
+4 stars
from 7,592 · score 1.61
31.zudochkin / awesome-newsletters
A list of amazing Newsletters
+4 stars
from 4,506 · score 1.61
32.dovecot / core
Dovecot mail server
+4 stars
from 1,271 · score 1.61
33.mail-in-a-box / mailinabox
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.
+3 stars
from 15,449 · score 1.39
34.lukencode / FluentEmail
All in one email sender for .NET. Supports popular senders (SendGrid, MailGun, etc) and Razor templates.
+3 stars
from 3,215 · score 1.39
35.leemunroe / responsive-html-email-template
A free simple responsive HTML email template
+2 stars
from 13,706 · score 1.10
36.rspamd / rspamd
Rapid spam filtering system.
+2 stars
from 2,558 · score 1.10
37.jstedfast / MimeKit
A .NET MIME creation and parser library with support for S/MIME, PGP, DKIM, TNEF and Unix mbox spools.
+2 stars
from 2,009 · score 1.10
38.FGRibreau / mailchecker
:mailbox: Cross-language temporary (disposable/throwaway) email detection library. Covers 55 734+ fake email providers.
+2 stars
from 1,915 · score 1.10
39.AfterShip / email-verifier
:white_check_mark: A Go library for email verification without sending any emails.
+2 stars
from 1,648 · score 1.10
40.novoid / Memacs
What did I do on February 14th 2007? Visualize your (digital) life in Org-mode
+2 stars
from 1,116 · score 1.10
41.mjmlio / mjml
MJML: the only framework that makes responsive email easy
+1 stars
from 18,283 · score 0.69
42.foxcpp / maddy
✉️ Composable all-in-one mail server.
+1 stars
from 6,115 · score 0.69
43.forwardemail / email-templates
Create, preview (browser/iOS Simulator), and send custom email templates for Node.js. Made for @forwardemail, @ladjs, @cabinjs, @spamscanner, and @breejs.
+1 stars
from 3,740 · score 0.69
44.emalderson / ThePhish
ThePhish: an automated phishing email analysis tool
+1 stars
from 1,381 · score 0.69
+1 stars
from 355 · score 0.69
46.cenfun / monocart-reporter
A playwright test reporter (Node.js)
+1 stars
from 325 · score 0.69
47.Intermesh / groupoffice
Group Office groupware and CRM
+1 stars
from 283 · score 0.69
48.acutario / ravenx
Notification dispatch library for Elixir applications
+1 stars
from 110 · score 0.69
49.danzuep / MailKitSimplified
Send and receive emails easily, fluently, with one line of code for each operation.
+1 stars
from 97 · score 0.69