Browse free open source Email Clients and projects below. Use the toggles on the left to filter open source Email Clients by OS, license, language, programming language, and project status.

  • Optimize your workforce. Icon
    Optimize your workforce.

    Avilar serves clients in the private, government and non-profit sectors, with 50 to 250,00 learners and administrative users.

    To win in today’s business environment, you need the right people, with the right skills, in the right jobs, at the right time. Avilar, the Competency Company, helps astute organizations optimize their workforce for success. Avilar’s competency and eLearning tools provide flexible workforce analytics solutions that work.
  • Need To Secure Your Public Cloud? Icon
    Need To Secure Your Public Cloud?

    Built for Developers, DevOps and Engineering Teams

    View all cloud assets of AWS, Google Cloud, Azure, Kubernetes, Digital Ocean in one place. Automates security misconfigurations of assets with guidance to resolve them. Covers far beyond basic checklists. It automatically evaluates the security misconfigs of the assets & provides step-by-step guidance to resolve them
  • 1
    Windows MBox Viewer

    Windows MBox Viewer

    Windows eml and mbox viewer.

    Free Windows Mbox Viewer. Gain access to mbox archives or single eml messages. View attachments and export single mails in eml format. Access large mbox files such as Google Takeout or Mozilla Thunderbird Archives. Development of mbox viewer continues now at github: https://github.com/eneam/mboxviewer **NOTE**: Windows Defender may sometimes report incorrectly that mbox-viewer contains malware. Please report the case to the development. Development will ask Windows Security to update Windows Defender rules to resolve the issue. Last time the incorrect detection was corrected by Microsoft Security within few hours. User will need to run Windows Update to install the latest updated detection rules.
    Leader badge
    Downloads: 2,240 This Week
    Last Update:
    See Project
  • 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: 72 This Week
    Last Update:
    See Project
  • 3
    SquirrelMail
    SquirrelMail is a PHP-based Web email client. It includes built-in pure PHP support for IMAP and SMTP, and renders all pages in pure HTML 4.0 for maximum compatibility across browsers. It has strong MIME support and a flexible plugin system.
    Leader badge
    Downloads: 596 This Week
    Last Update:
    See Project
  • 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: 23 This Week
    Last Update:
    See Project
  • Manage your IT department more effectively Icon
    Manage your IT department more effectively

    Streamline your business from end to end with ConnectWise PSA

    ConnectWise PSA (formerly Manage) allows you to stop working in separate systems, and helps you build a more profitable business. No more duplicate data entries, inefficient employees, manual invoices, and the inability to accurately track client service issues. Get a behind the scenes look into the award-winning PSA that automates processes for each area of business: sales, help desk, support, finance, and HR.
  • 5
    Outlook Mail Merge Attachment is a script which can be used to add an attachment to an mail merge in Microsoft Outlook.
    Leader badge
    Downloads: 185 This Week
    Last Update:
    See Project
  • 6
    NOCC
    NOCC is a simple and fast Webmail client which can handle POP3 and IMAP mailboxes and sends email via SMTP. It is written with PHP, has low requirements (no database, frames). Features multi-language support, MIME attachments, displays HTML messages. The installation guide comes with the source code: https://sourceforge.net/p/nocc/code/HEAD/tree/trunk/webmail/docs/INSTALL If you encounter problems or bugs you can always try the current HEAD version: https://sourceforge.net/p/nocc/code/HEAD/tarball?path= Questions, bug reports or support requests are very welcome: https://sourceforge.net/p/nocc/_list/tickets Alternative source code repository: https://github.com/oheil/NOCC
    Downloads: 97 This Week
    Last Update:
    See Project
  • 7
    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! K-9 Mail also offers a light and dark theme, keyboard shortcuts and emoji support. Like man's best friend, K-9 Mail is an email client you can depend on, and will surely be your best friend when it comes to handling your emails!
    Downloads: 2 This Week
    Last Update:
    See Project
  • 8
    Trojitá, a Qt IMAP e-mail client
    Leader badge
    Downloads: 106 This Week
    Last Update:
    See Project
  • 9
    PoptrayU

    PoptrayU

    Email Notifier For Windows

    This email notifier sits in your system tray and pops up a notification when new messages arrive. Preview your email before downloading it to your mail client or launching webmail applications. Create rules to delete or change the priority of messages. This program builds upon the open source PopTray mail notifier adding many new features including Windows Vista/7/8/10 support, UTF-8 and unicode support, HTML Preview, IMAP support, TLS & SASL support, etc.
    Leader badge
    Downloads: 34 This Week
    Last Update:
    See Project
  • Precoro helps companies spend smarter Icon
    Precoro helps companies spend smarter

    Fully Automated Process in One Tool: From Purchase Orders to Budget Control and Reporting.

    For minor company expenses, you might utilize a spend management solution or track everything in spreadsheets. For everything more, you'll need Precoro. We help companies achieve procurement excellence and budget efficiency by building transparent, predictable, automated spending workflows.
  • 10

    HERMES Mail

    The cult-favourite eMail client formerly known as Qualcomm Eudora

    eMail traffic is on the rise. With over 100 man-years of development time behind it and a clean, intuitive interface that makes handling messages a breeze, Hermes Messenger (formerly known as QUALCOMM Eudora) is more than a way to send and receive mail: it's a powerful management tool with features to increase your productivity and enhance your communications. It is the best eMail program for people who get lots of it. If you're not yet one of them, you soon will be. Take control of your eMail before it takes control of you! Hermes provides industrial-strength communication, free of ads and free of cost.
    Leader badge
    Downloads: 32 This Week
    Last Update:
    See Project
  • 11
    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 folders and send outbound messages with SMTP. Cypht is an application built entirely of plugins, or as we call them, module sets (which is obviously way cooler sounding than plugins), that are executed by the framework. Modules provide a flexible way to add new features or customize the program without hacking the code. Cypht is Open Source (LGPL V2), and written in PHP and JavaScript.
    Downloads: 1 This Week
    Last Update:
    See Project
  • 12
    Magic Mail Monitor3 - Windows mail checker with multiple mailboxes support, ability to preview and delete messages. Based on original code of Magic Mail Monitor from Valeriy Ovechkin.
    Downloads: 18 This Week
    Last Update:
    See Project
  • 13
    PopTray is a mail notifier written in Delphi for the Windows platform. It sits in your tray notification area and check mail from multiple accounts on a timer interval. Preview, Delete, Rules, Plug-ins and translated into more than 30 languages.
    Downloads: 18 This Week
    Last Update:
    See Project
  • 14
    Add support for making Gmail the default mail application for the GNOME desktop. "Gmail" will be a choice for Mail Reader in the Preferred Applications dialog. "Mailto" links, "Send Link", etc., will be handled by Gmail.
    Downloads: 10 This Week
    Last Update:
    See Project
  • 15
    E-mail Spoofer is a tool designed for penetration testers who need to send phishing e-mails. It allows to send mails to a single recipient or a list, it supports plain text/html email formats, attachments, templates and more... Update Version 1.1: =============== * Added text conversion to Homographs for bypassing spam filters. (based on http://www.exploit-db.com/wp-content/themes/exploit/docs/20114.pdf) * Added Reply-To header * Added Sender Name Field * Added Built in User Agent * Detailed error log If you find this tool useful crypto currency donations are welcome: Bitcoin: 1Kksc9b4WZ5X36xGDgpodPVpBSozMje6ui Litecoin: LQ1JCMxo122FpJ8iKX7HsrNtjCacpTkkFW
    Leader badge
    Downloads: 22 This Week
    Last Update:
    See Project
  • 16
    This is an open source Email client for Borland Delphi with source code. It uses Indy controls as well as PBears HTML Viewer Component and BSALA EmbeddedWB (updated versions for Delphi 2009 are here). It is IMAP, POP3, MAPI and SMTP compatible.
    Downloads: 9 This Week
    Last Update:
    See Project
  • 17
    SaltOS

    SaltOS

    SaltOS, ERP, CRM, Business Management Suite, Josep Sanz Campderrós

    SaltOS is a Business Management solution 100% Cloud Computing. It integrates features like CRM (Customer Relation Management) and ERP (Enterprise Resource Planning). Moreover is it licensed as 100% free software GPL-3.0.
    Downloads: 7 This Week
    Last Update:
    See Project
  • 18

    MorphyMail Free Email Marketer

    Create, send and track Unlimited bulk emails for Free

    Desktop software for windows to create, send and track unlimited bulk emails for lifetime for free. Includes 500 email templates , automated bounce and subscription processing, spam checker, WYSIWYG HTML editor, google analytics and social media integration, automated delivery tracking to track opens , clicks and geolocation of recipients, multithreaded engine for fast delivery of emails, website forms integration, scheduled mailing and much more features. It is a 100% free software to send unlimited bulk emails for lifetime.
    Downloads: 4 This Week
    Last Update:
    See Project
  • 19
    Outlook Open Converter

    Outlook Open Converter

    Convert Outlook and Outlook Express files to open formats

    Tiny application based on readpst and dbxconv that provides a convenient GUI to convert Outlook and Outlook Express files into open standards. The program converts Outlook Express 5/6 .DBX to .EML and Outlook 2003/2007/2010 .PST to MBOX. The program runs only on Linux machines and doesn't need any Microsoft software!
    Downloads: 11 This Week
    Last Update:
    See Project
  • 20
    Gmail Herald

    Gmail Herald

    Be aware of new message in your mailbox

    Gmail Herald is Qt based application that alerts when you have new Gmail messages and allows to mark them as read. It displays an icon in your system tray to let you know if you have unread emails, and shows you their subjects, senders and snippets, all without a web browser.
    Downloads: 6 This Week
    Last Update:
    See Project
  • 21
    G4J is a set of API that communicate to GMail. Use this API to login, retrive/search/browse message, download attachment and do others action on GMail account! An email application (Gmailer for java) is included to demonstrate the usage of the API.
    Downloads: 3 This Week
    Last Update:
    See Project
  • 22
    jwSMTP, Send email programmatically (C++ code/lib). Linux, BSD, Windows etc. Attachments, Multiple recipients, Cc/Bcc recipients supported. MX lookup or send to an SMTP server direct. LOGIN and PLAIN authentication now supported. Html or plain text forma
    Downloads: 7 This Week
    Last Update:
    See Project
  • 23
    Advanced email suite.
    Downloads: 12 This Week
    Last Update:
    See Project
  • 24
    GoldBug - Encrypted Communications

    GoldBug - Encrypted Communications

    Chat Messenger. E-Mail-Client. Websearch. Filetransfer.

    GoldBug is a decentralized & secure communication suite that offers an integrated e-mail client, an instant messenger & a file transfer. Also included is an URL-RSS-DB & a p2p web search. Current vers. w/ McEliece Algorithm. GoldBug has been 2013 - 2023 ten years just another Graphical User Interface of the Spot-On Encryption Suite. Main GUI features: Minimal & colorful Interface with Tabs in the East. Microsoft & Qt MinGW deprecated Win32 & for Compiling: ● https://sourceforge.net/p/goldbug/wiki/compiling As Spot-On implemented the minimal GB-concept & Nuvola Icons, GoldBug has now been fully integrated into Spot-On Win64: Just choose Tabs at East & Mini-View in Options - w/ Nuvola Icons of course! Voilá! & Many Thanks, Pro-Files can be found archived at ● current source: https://github.com/textbrowser/spot-on ● EN Manual: https://www.amazon.com/dp/3749435065 ● DE: https://compendio.github.io/goldbug-manual-de/ ● Study: https://www.amazon.com/asin/dp/3750408971
    Downloads: 9 This Week
    Last Update:
    See Project
  • 25
    Heirloom mailx (formerly known as "nail") is intended provide the functionality of the POSIX mailx command with additional support for MIME messages, IMAP (including caching), POP3, SMTP, S/MIME, message threading/sorting, scoring, and filtering.
    Downloads: 5 This Week
    Last Update:
    See Project
  • Previous
  • You're on page 1
  • 2
  • 3
  • 4
  • 5
  • Next

Guide to Open Source Email Clients

Open source email clients are a type of software that allow users to access and manage their email accounts without the use of proprietary software. Open source email clients have become popular due to their flexibility, customization options, cost savings, and security features.

One of the main benefits of using an open source email client is its flexibility. These programs usually come with pre-installed plugins or add-ons that allow users to customize the interface according to their needs and preferences. They also give users more control over how messages are organized and presented within the inbox. This includes arranging content by sender, subject line, size, attachments and other variables for easier managing of emails received from multiple sources. Additionally, these programs often support different languages for international usage.

Another benefit of using open source is cost savings since there is no need for purchasing expensive subscription plans offered by closed-source companies. This makes it ideal for those who do not want to settle for basic features offered by generic email providers such as Gmail or Outlook but still want all the necessary capabilities at no additional charge.

In addition, open source solutions are often more secure than closed-source ones because they contain fewer vulnerabilities that can be exploited by malicious actors. Such software undergoes regular reviews by independent volunteers in order to identify any issues with code updates or releases before they go live into production systems where they can cause damage or disruption in service availability if not checked properly beforehand in an appropriate sandbox environment first among other processes carried out during development phases like peer review analysis approved by community members consisting developers specialized in working on this specific application as well other security experts hired especially checking on safety related matters concerning incoming hotfixes among others which will help reduce potentially ill effects posed towards end user’s computing experience over time thanks again thanks their dedicated efforts conducted under non profit driven logic purposes. As such this provides more confidence when handling sensitive information sent through such technologies instead putting trust solely on third party applications made available through commercial services produced overseas localizations too due tight restrictions placed around them (e.g license agreements) leading potential exposure dangerous user data being accessible unsecure environments.

Overall, open source email clients offer many advantages compared to traditional services including greater flexibility in customizing your experience along with cost savings plus improved security measures making them attractive alternatives those looking more control over how manage their communications internet age where privacy matters have finally started taking upper stage amongst public sphere conversations ongoing day after day long lasting politically driven events taking place world wide whenever applicable case scenario situations arise lead unexpected results.

Open Source Email Clients Features

  • Composing Messages: Open source email clients allow users to write, modify and delete messages as necessary. They also have the capability to attach files, add formatting or even insert images into emails before sending.
  • Group Messaging: Open source email clients provide the ability to send out emails to a large list of individuals at once quickly and efficiently using mail merge capabilities.
  • Archiving & Filing: These email programs have powerful archiving features which make it easy to sort through old emails and organize them into folders for future reference.
  • Filtering & Searching: Email clients enable users to find specific messages easily by using keyword searches through their inboxes, as well as create filters which will automatically separate new incoming emails according to certain criteria that is set up by the user.
  • Spam Protection: Many open source email clients provide built-in spam protection features that flag suspicious emails so that users can easily recognize what is genuine communication and what isn't.
  • Security & Privacy: Open source email programs offer high levels of encryption for messages sent between two parties, making sure all data remains secure from prying eyes. Additionally, most platforms offer access logs which tell users when an email was opened or downloaded from another user's account – helping further protect sensitive information from being viewed without consent.

What Types of Open Source Email Clients Are There?

  • Desktop Clients: These are email programs that must be installed on a computer and can usually be used without an internet connection. They often have more features than web and mobile clients, such as support for offline access, comprehensive customization options, better security and privacy settings, etc.
  • Web Clients: This type of email client runs in a browser and requires an internet connection to function. It’s convenient for people who use multiple computers or devices since their emails will always be up-to-date on each machine or device.
  • Mobile Clients: These are optimized versions of desktop or web clients specifically designed to work on mobile devices such as smartphones and tablets. They offer convenience when it comes to managing emails while away from home or office.
  • Command-Line Clients: These are console-based email programs that operate entirely via text commands instead of user interfaces like the ones found in desktop or web clients—useful for experienced users who prefer using the command line rather than GUIs (graphical user interfaces).

Benefits of Open Source Email Clients

  1. Increased Security: Open source email clients provide users with enhanced security compared to commercial closed-source email services. By allowing the code to be publicly available, individuals or groups can review and test it for any potential vulnerabilities that might not have been identified by developers. This helps to ensure that user data is always secure.
  2. Increased Customizability: Open source email clients also allow users greater flexibility and customization than closed-source systems. As the code is accessible, developers are able to create custom plugins, add-ons, and other features tailored specifically for individual needs. Additionally, open source projects may offer more options when it comes to managing large amounts of emails or automating tedious tasks such as sorting through emails by labels.
  3. Reduced Cost: In comparison with closed-source software solutions, open source options are generally much less expensive over time as they are free (or inexpensive) up front and often require minimal maintenance costs due to the large community of contributors constantly working on them. This makes them perfect for small businesses or organizations who cannot afford costly enterprise solutions.
  4. Increased Reliability: Since many developers have access to an open source project’s codebase, this allows for rapid bug fixes or improvements which increase reliability across different platforms or operating systems over time - opposed to closed-source applications which may take longer due to developer restrictions or resources needed in order to solve a particular issue.
  5. Experienced Community Support: Finally, one of the biggest benefits of using an open source client is having access to a knowledgeable community of users willing and eager to help out anyone who has questions about their program – whether it be technical support for adding additional features/plug ins or just general advice about how best use the platform.

What Types of Users Use Open Source Email Clients?

  • Power Users: Those who use open source email clients to gain access to additional features and customization options, such as filters or better integration with other programs.
  • Hobbyists: Those who enjoy tinkering with their software and like the challenge of maintaining an open source client.
  • Businesses: Companies that prefer to use open source software because it is often free and provides a high level of flexibility when it comes to configuring or customizing programs.
  • Security-conscious users: People who want the added protection of open protocols for their online communication and data storage needs.
  • Flexibility seekers: Individuals looking to move away from traditional closed-source platforms, opting instead for something that may offer more freedom in terms of features, development, or security.
  • Multiplatform users: Those who need a single platform compatible with multiple operating systems (Windows, MacOS, Linux).
  • Beginners: Novice computer users looking for an easy-to-use email client without detailed technical knowledge.

How Much Does Open Source Email Clients Cost?

Open source email clients are completely free of cost. They come with a variety of features and benefits, such as being platform independent, meaning they can work on almost any operating system or device. Compared to proprietary software that may charge an annual fee or require a license upon installation, open source is much more budget-friendly while still providing the same levels of security and functionality. The fact that code is openly available also makes it easier for developers to identify security vulnerabilities quickly and patch them soon after. Additionally, since open source email clients are constantly updated by the community, users don’t need to worry about purchasing upgrades each time a new version comes out – you’ll always have access to the latest greatest features without spending a dime.

What Software Can Integrate With Open Source Email Clients?

Open source email clients can integrate with a variety of software types to streamline workflows and increase efficiency. Examples of such software include calendar applications, project management tools, task tracking platforms, customer support systems, accounting solutions, and analytics packages. Many of these services are provided by third-party vendors who specialize in integration services for open source email clients. Additionally software such as document storage systems like Dropbox or Google Drive can often be used to increase productivity when working with an open source email client. This type of integration allows users to attach documents directly from their cloud storage solutions to emails without needing to download them locally. With the wide variety of available software types that can integrate with open source email clients, users have many options for creating effective workflows that help maximize productivity.

Open Source Email Clients Trends

  1. Increased Popularity: Open source email clients have seen a steep rise in popularity over the past few years as more people are looking for an alternative to traditional email providers. This is due to the increasing number of features and flexibility these open source clients offer.
  2. Increased Security: Open source email clients provide greater security compared to traditional email providers, as they are not owned by any single company or organization. This means that user data is more secure and less vulnerable to malicious attacks.
  3. Customizability: Open source email clients offer a level of customizability that traditional email providers cannot match. This means users can tailor the client to their individual needs and preferences, allowing for greater control and customization.
  4. Cross Platform Compatibility: Open source email clients are usually available on multiple platforms, making them more accessible to users who may be using different devices or operating systems.
  5. Free of Charge: One of the biggest advantages of using an open source email client is that they are usually free of charge, allowing users to save money compared to paid subscriptions from traditional providers.

How To Get Started With Open Source Email Clients

Getting started with an open source email client is relatively easy. First, you will need to choose the appropriate software for your needs from the myriad of available options. Popular open source email clients include Mozilla Thunderbird, K-9 Mail, and Claws Mail among others.

Once a suitable choice has been made, download and install the software onto your device. Next, you will be required to set up an account by providing various details such as your name, email address and password (for security measures). You may also be asked to provide other information such as server settings or mail protocols. Different clients might have different steps but they should almost always require you to configure a POP3 or IMAP server. This is done in order to fetch emails that are hosted on external servers like Gmail or Yahoo. Often times this requires knowledge of specific ports and encryption types used by those services so it’s best to refer their documentation if possible.