Showing 650 open source projects for "email client"

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  • 1
    Thunderbird for iOS

    Thunderbird for iOS

    Open Source Email App for iOS

    Thunderbird iOS is the official iPhone and iPad email client offering from the Thunderbird project, bringing the capabilities of a feature-rich, open-source email experience to iOS devices with native UI and Apple platform integrations. The app gives users a powerful tool for managing multiple email accounts, including IMAP and POP3 configurations, and supports modern authentication flows like OAuth for popular providers.
    Downloads: 39 This Week
    Last Update:
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  • 2
    Mailspring

    Mailspring

    A faster, leaner email client and fork of Nylas Mail

    Mailspring is a fast and lean mail client that’s a new version of Nylas Mail. It’s maintained by one of Nylas Mail’s original authors, with plenty of great features and enhancements such as a new C++ sync engine that allows it to use 50% less RAM. Heavy dependencies have also been removed and the package manager rewritten for even greater speed. Written in TypeScript with Electron and React, it is cross-platform (macOS, Windows and Linux) and designed to be easy to extend.
    Downloads: 51 This Week
    Last Update:
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  • 3
    Foundation for Emails

    Foundation for Emails

    Design responsive HTML emails that work on any device & email client

    Foundation for Emails is a framework that allows you to create responsive HTML emails that work on any device and on any email client, even Outlook. All of its HTML/CSS components have been tested, ensuring consistency across every major email client. Foundation for Emails consists of a solid set of customizable components, including a fully responsive grid, typography, alignment classes and more. It also has a new templating language, Inky, that makes it easier than ever to write HTML emails. ...
    Downloads: 4 This Week
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  • 4
    Tutanota

    Tutanota

    Open source email service with a strong focus on security and privacy

    Tutanota is an open source email client focused on security and privacy. It is built with end-to-end encryption and 2FA, so you can be assured of utmost email security. Tutanota is always encrypted, so whether you’re using their secure webmail client, mobile apps or desktop clients, you can be sure to communicate securely.
    Downloads: 12 This Week
    Last Update:
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  • 5
    K-9 Mail

    K-9 Mail

    Open Source Email App for Android

    K-9 Mail is an advanced, open-source email client for Android that's focused on making it easy to chew through large volumes of email. It's designed to be easy to use by both novice and power users, with plenty of useful features. It has IMAP push email support, support for multiple accounts, support for POP3 and Exchange 2003/2007 (with WebDAV), flagging, filing, signatures and more!
    Downloads: 5 This Week
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  • 6
    Thunderbird for Android

    Thunderbird for Android

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

    Thunderbird Android is the mobile counterpart of the popular Thunderbird email client, reimagined for Android phones and tablets so users can access, send, and organize email from multiple accounts with advanced features found in desktop clients. It embraces modern mobile UI design while supporting robust email protocols (IMAP/POP3) and standards like OAuth for secure logins to services such as Gmail, Outlook, or custom mail providers.
    Downloads: 6 This Week
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  • 7
    Proton Mail Bridge

    Proton Mail Bridge

    Proton Mail Bridge application

    Proton Mail Bridge is a desktop application that runs in the background on Windows, macOS, and Linux to enable users to access their Proton Mail encrypted email accounts with traditional email clients like Outlook, Thunderbird, Apple Mail, and others via local IMAP/SMTP servers. Because standard IMAP cannot natively decrypt end-to-end encrypted messages, Bridge acts as a translator that downloads encrypted mail, decrypts it locally, and serves it to your preferred mail client over a local server, while encrypting outgoing messages before they’re sent to Proton’s servers. ...
    Downloads: 8 This Week
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  • 8
    SMTP Tunnel Proxy

    SMTP Tunnel Proxy

    A high-speed covert tunnel that disguises TCP traffic as SMTP email

    SMTP Tunnel Proxy is a high-speed covert tunneling proxy that disguises regular TCP traffic as legitimate SMTP email communication to evade deep packet inspection (DPI) firewalls and censorship systems. It implements a SOCKS5 proxy interface on the client that wraps outbound traffic into an SMTP-like handshake (EHLO, STARTTLS, AUTH) and encrypted payload, making the session appear to DPI systems as a normal email exchange. The tool supports modern TLS encryption (STARTTLS) with HMAC-SHA256 authentication, per-user secrets, IP whitelisting, and multiplexed connections over a single tunnel. ...
    Downloads: 3 This Week
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  • 9
    Cypht

    Cypht

    Lightweight Open Source webmail written in PHP and JavaScript

    All your E-mail, from all your accounts, in one place. Cypht is not your father's webmail. Unless you are one of my daughters, in which case it is your father's webmail. Cypht is like a news reader, but for E-mail. Cypht does not replace your existing accounts - it combines them into one. And it's also a news reader. The driving force behind Cypht development is to provide combined views for multiple accounts, but it's also a standard E-mail client that lets you browse and manage IMAP...
    Downloads: 2 This Week
    Last Update:
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  • 10
    Proton Mail for iOS

    Proton Mail for iOS

    Secure email that protects your privacy

    Proton Mail for iOS is the official iPhone and iPad client that brings Proton’s secure, end-to-end encrypted email service to Apple’s mobile ecosystem, combining strong privacy protections with native performance and gestures. The app allows users to sign in to one or multiple Proton Mail accounts, read and compose encrypted messages, schedule emails, protect emails with passwords, set expiration timers, and organize mail with labels and folders inside a smooth, intuitive iOS interface. ...
    Downloads: 1 This Week
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  • 11
    Mail-in-a-Box

    Mail-in-a-Box

    Take back control of your email with this mail server 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. Mail-in-a-Box lets you become your own mail service provider in a few easy steps. It’s sort of like making your own gmail, but one you control from top to bottom. Technically, Mail-in-a-Box turns a fresh cloud computer into a working mail server. But you don’t need to be a technology expert to set it up. Our goals are to make deploying...
    Downloads: 4 This Week
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  • 12
    ElectronMail

    ElectronMail

    Unofficial ProtonMail Desktop App

    ElectronMail is an Electron-based unofficial desktop client for ProtonMail. The app aims to provide enhanced desktop user experience enabling features that are not supported by the official in-browser web clients. It is written in TypeScript and uses Angular. The way of verifying that the installation packages attached to the releases have been assembled from the source code is being provided.
    Downloads: 7 This Week
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  • 13
    MJML 4

    MJML 4

    The only framework that makes responsive-email easy

    MJML is a markup language created by Mailjet and designed to reduce the pain of coding a responsive email. Its semantic syntax makes the language easy and straightforward while its rich standard components library shortens your development time and lightens your email codebase. MJML’s open-source engine takes care of translating the MJML you wrote into responsive HTML.
    Downloads: 0 This Week
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  • 14
    Proton Web Clients

    Proton Web Clients

    Monorepo hosting the proton web clients

    Proton Web Clients is a monorepo hosting the web applications for Proton’s suite of privacy-focused services, including the core Proton Mail webmail interface and related web apps like Proton Calendar, Proton Drive, Proton Account, Proton VPN, Proton Pass, and other connected tools. It consolidates all web client code, shared modules, dependencies, and development tooling into a single repository, enabling unified maintenance, consistency of design patterns, and efficient evolution of Proton’s online interfaces. These web clients run entirely in the browser, letting users securely interact with their email, calendars, files, and other services without needing native software installed, and benefiting from end-to-end encryption where applicable. ...
    Downloads: 0 This Week
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  • 15
    Proton Mail for Android

    Proton Mail for Android

    Proton Mail Android app

    ...It supports composing messages, viewing attachments, handling contacts, and configuring account and mail settings from within the app, giving users portable access to their secure inbox wherever they go. Because ProtonMail’s service never sees unencrypted content, the Android client performs necessary encryption and decryption on the device, aligning with Proton’s privacy-first philosophy and open-source security model.
    Downloads: 0 This Week
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  • 16
    Invoice Ninja

    Invoice Ninja

    Free and Open Source Invoicing, Expenses & Time-Tracking

    Invoice Ninja is a free and open source invoicing, expenses and time-tracking app built with Laravel and Flutter. It offers a plethora of great features, including custom branded invoice design, recurring invoicing and auto-bill clients, real-time quote creation and custom proposals, expense reporting and so much more! Invoice Ninja is also capable of handling online payments from more than 40 payment gateways, including Stripe, PayPal and WePay. It also accepts payments using credit cards,...
    Downloads: 24 This Week
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  • 17
    PyFCM

    PyFCM

    Python client for FCM - Firebase Cloud Messaging

    Python client for FCM - Firebase Cloud Messaging (Android, iOS and Web) Firebase Cloud Messaging (FCM) is the new version of GCM. It inherits the reliable and scalable GCM infrastructure, plus new features. GCM users are strongly recommended to upgrade to FCM. Using FCM, you can notify a client app that new email or other data is available to sync.
    Downloads: 0 This Week
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  • 18
    Session for Android

    Session for Android

    A Decentralized, Onion Routed, Private Messenger

    Session Android is the official mobile client for Session, a privacy-first messaging protocol that enables secure, anonymous messaging without requiring phone numbers, email addresses, or centralized user accounts. Built natively for Android, the app lets users send and receive end-to-end encrypted text messages, voice notes, images, and attachments in both one-on-one and group chats, all while routing data through a decentralized onion-routing network designed to protect not just message content but also metadata like sender ID, timing, and network location. ...
    Downloads: 7 This Week
    Last Update:
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  • 19
    next-forge

    next-forge

    Production-grade Turborepo template for Next.js apps

    A mono repo template designed to have everything you need to build your new SaaS app as quickly as possible. Authentication, billing, analytics, SEO, database ORM and more. Create and preview email templates with a React-based email library. A twblocks website template with a type-safe blog, bulletproof SEO, and legal pages, powered by Content Collections. Simple, beautiful out of the box, and easy-to-maintain documentation. Use Prisma Studio to visualize your database, and generate Prisma client code.
    Downloads: 0 This Week
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  • 20
    EasyAppointments

    EasyAppointments

    Easy!Appointments - Self Hosted Appointment Scheduler

    Easy!Appointments is an open-source appointment management system that helps businesses schedule and manage client appointments efficiently. It offers a web-based interface where clients can book appointments online, while administrators can manage staff schedules, services, and customer data. The system is highly customizable and can be integrated with other tools like Google Calendar, making it ideal for small businesses, clinics, and service providers.
    Downloads: 5 This Week
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  • 21
    Session Desktop

    Session Desktop

    A Decentralized, Onion Routed, Private Messenger

    Session Desktop is an open-source, privacy-focused messaging application that brings secure, decentralized communication to desktop environments such as Windows, macOS, and Linux, providing users with encrypted text, media, and group chats without requiring phone numbers or email addresses. Built on the Session protocol and the Loki network, it routes messages through a distributed onion-routing network that hides metadata like sender, timing, and location so that conversations are resistant to surveillance and correlation attacks. The desktop client pairs seamlessly with Session mobile apps but can also be used independently to communicate with Session contacts in a familiar desktop interface that supports a full keyboard, global notifications, drag-and-drop media sharing, and local file access. ...
    Downloads: 13 This Week
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  • 22
    gotrue-js

    gotrue-js

    An isomorphic Javascript library for GoTrue

    An isomorphic JavaScript client library for the GoTrue API. gotrue-js uses the cross-fetch library to make HTTP requests, but an alternative fetch implementation can be provided as an option. This is most useful in environments where cross-fetch is not compatible.
    Downloads: 0 This Week
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  • 23
    PassKit PHP SDK

    PassKit PHP SDK

    PHP SDK for Apple Wallet and Google Pay Membership, Loyalty, etc.

    Golang SDK for Apple Wallet and Google Pay membership, loyalty, event tickets, access cards, coupons & flights. Use the PassKit PHP gRPC SDK to issue and manage Apple Wallet and Google Pay Passes from your PHP application. Simply request your SDK credentials from the PassKit Portal. You will receive an email with your credentials on your registered email address. Follow the instructions in the email to decrypt key.pem, and then copy the .pem files into your project (in this project & for the...
    Downloads: 0 This Week
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  • 24
    SmsForwarder

    SmsForwarder

    Monitors Android mobile phone text messages, calls, and notifications

    ...The tool’s functionality extends to remote control features, which allow a paired server or client to query messages, calls, contacts, and more.
    Downloads: 9 This Week
    Last Update:
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  • 25
    MailCatcher

    MailCatcher

    Catches mail and serves it through a dream

    Catches mail and serves it through a dream. MailCatcher runs a super simple SMTP server that catches any message sent to it to display in a web interface. Run mailcatcher, set your favorite app to deliver to smtp://127.0.0.1:1025 instead of your default SMTP server, then check it out to see the mail that's arrived so far. Shows HTML, Plain Text and Source version of messages, as applicable. Rewrites HTML enabling display of embedded, inline images/etc and opens links in a new window....
    Downloads: 1 This Week
    Last Update:
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