Email Clear Filters

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

  • Migrate to innovate with Red Hat Enterprise Linux on Azure Icon
    Migrate to innovate with Red Hat Enterprise Linux on Azure

    Streamline your IT modernization journey with a holistic environment running Red Hat Enterprise Linux on Azure.

    With Red Hat Enterprise Linux on Azure, businesses can confidently modernize their IT environment, knowing they don’t have to compromise on security, scalability, reliability, and ease of management. Securely accelerate innovation and unlock a competitive edge with enterprise-grade modern cloud infrastructure.
  • Automated RMM Tools | RMM Software Icon
    Automated RMM Tools | RMM Software

    Proactively monitor, manage, and support client networks with ConnectWise Automate

    Out-of-the-box scripts. Around-the-clock monitoring. Unmatched automation capabilities. Start doing more with less and exceed service delivery expectations.
  • 1
    Scrollout F1

    Scrollout F1

    An easy-to-use anti-spam email gateway

    • Designed for Linux and Windows email system administrators, Scrollout F1 is an easy to use, already adjusted email firewall (gateway) offering free anti-spam and anti-virus protection aiming to secure existing email servers, old or new, such as Microsoft Exchange, Lotus Domino, Postfix, Exim, Sendmail, Qmail and others. • Built-in multilayer security levels make configuration effort equal to a car radio. • It combines simplicity with effective protection using powerful open source with additional set of rules & filters. • Available as 64bit: - ISO image (Internet connection required during installation) - install from scratch (Internet connection required during installation). • Minimum Requirements (for 5,000 messages/day): 1 GB of RAM 30 GB storage drive 1 Processor x86/AMD64 1 Ethernet x 1 IPv4 address UDP ports: 53 123 4500 6277 24441 TCP ports: 25 80 443 2703
    Leader badge
    Downloads: 170,797 This Week
    Last Update:
    See Project
  • 2
    Anti-Spam SMTP Proxy Server

    Anti-Spam SMTP Proxy Server

    Anti-Spam SMTP Proxy Server implements multiple spam filters

    The Anti-Spam SMTP Proxy (ASSP) Server project aims to create an open source platform-independent SMTP Proxy server which implements auto-whitelists, self learning Hidden-Markov-Model and/or Bayesian, Greylisting, DNSBL, DNSWL, URIBL, SPF, SRS, Backscatter, Virus scanning, attachment blocking, Senderbase and multiple other filter methods. Click 'Files' to download the professional version 2.8.1 build 23131. A linux(ubuntu 20.04 LTS) and a freeBSD 12.2 based ready to run OVA of ASSP V2 are also available for download. NOTICE: V1 development has been stopped at the end of 2014 (1.10.1 build 16060). Possibly there will be done some bugfixing in future. Please upgrade to V2, which is and will be actively maintained.
    Leader badge
    Downloads: 73,370 This Week
    Last Update:
    See Project
  • 3
    PHPMailer

    PHPMailer

    The classic email sending library for PHP

    PHPMailer – A full-featured email creation and transfer class for PHP. Support for UTF-8 content and 8bit, base64, binary, and quoted-printable encodings. SMTP authentication with LOGIN, PLAIN, CRAM-MD5, and XOAUTH2 mechanisms over SMTPS and SMTP+STARTTLS transports. Validates email addresses automatically. Many PHP developers need to send email from their code. The only PHP function that supports this directly is mail(). However, it does not provide any assistance for making use of popular features such as encryption, authentication, HTML messages, and attachments. Formatting email correctly is surprisingly difficult. There are myriad overlapping (and conflicting) standards, requiring tight adherence to horribly complicated formatting and encoding rules – the vast majority of code that you'll find online that uses the mail() function directly is just plain wrong, if not unsafe!
    Downloads: 286 This Week
    Last Update:
    See Project
  • 4
    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: 96 This Week
    Last Update:
    See Project
  • Innovate faster with enterprise-ready generative AI—enhanced by Gemini Icon
    Innovate faster with enterprise-ready generative AI—enhanced by Gemini

    Build, deploy, and scale machine learning (ML) models faster, with fully managed ML tools for any use case.

    Vertex AI offers everything you need to build and use generative AI—from AI solutions, to Search and Conversation, to 130+ foundation models, to a unified AI platform.
  • 5
    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: 2,029 This Week
    Last Update:
    See Project
  • 6
    theHarvester

    theHarvester

    E-mails, subdomains and names

    theHarvester is a very simple to use, yet powerful and effective tool designed to be used in the early stages of a penetration test or red team engagement. Use it for open source intelligence (OSINT) gathering to help determine a company's external threat landscape on the internet. The tool gathers emails, names, subdomains, IPs and URLs using multiple public data sources.
    Downloads: 75 This Week
    Last Update:
    See Project
  • 7
    MOSINT

    MOSINT

    An automated e-mail OSINT tool

    MOSINT is the fastest OSINT Tool for emails. It helps you gather information about the target email. Email validation, check social accounts, check data breaches and password leaks, finding related emails and domains, scan Pastebin Dumps. Google Search and DNS Lookup.
    Downloads: 65 This Week
    Last Update:
    See Project
  • 8
    MailHog

    MailHog

    Web and API based SMTP testing

    Inspired by MailCatcher, easier to install. Built with Go, MailHog runs without installation on multiple platforms. Run it from Docker Hub or using the provided Dockerfile. The SMTP server starts on port 1025, the HTTP server starts on port 8025, in-memory message storage. ESMTP server implementing RFC5321. Support for SMTP AUTH (RFC4954) and PIPELINING (RFC2920). Web interface to view messages (plain text, HTML or source). Supports RFC2047 encoded headers. Real-time updates using EventSource. Release messages to real SMTP servers. Chaos Monkey for failure testing. HTTP API to list, retrieve and delete messages. See APIv1 and APIv2 documentation for more information. HTTP basic authentication for MailHog UI and API. Multipart MIME support. Download individual MIME parts. In-memory message storage. MongoDB and file based storage for message persistence. Lightweight and portable. No installation required.
    Downloads: 64 This Week
    Last Update:
    See Project
  • 9

    milter manager

    Protects you from spam mails and virus mails effectively with milter

    This project has been moved to https://milter-manager.osdn.jp/ milter manager protects you from spam mails and virus mails effectively with milter. milter manager has embedded Ruby interpreter to control milters flexibly. milter manager can be used with Sendmail on Postfix on Ubuntu, CentOS, FreeBSD and so on.
    Leader badge
    Downloads: 4,287 This Week
    Last Update:
    See Project
  • Claims Processing solution for healthcare practitioners. Icon
    Claims Processing solution for healthcare practitioners.

    Very easy to use for medical, dental and therapy offices.

    Speedy Claims became the top CMS-1500 Software by providing the best customer service imaginable to our thousands of clients all over America. Medical billing isn't the kind of thing most people get excited about - it is just a tedious task you have to do. But while it will never be a fun task, it doesn't have to be as difficult or time consumimg as it is now. With Speedy Claims CMS-1500 software you can get the job done quickly and easily, allowing you to focus on the things you love about your job, like helping patients. With a simple interface, powerful features to eliminate repetitive work, and unrivaled customer support, it's simply the best HCFA 1500 software available on the market. A powerful built-in error checking helps ensure your HCFA 1500 form is complete and correctly filled out, preventing CMS-1500 claims from being denied.
  • 10
    Blat - Windows Command Line SMTP Mailer
    Blat - A Windows (32 & 64 bit) command line SMTP mailer. Use it to automatically eMail logs, the contents of a html FORM, or whatever else you need to send.
    Leader badge
    Downloads: 910 This Week
    Last Update:
    See Project
  • 11
    King Phisher

    King Phisher

    Phishing Campaign Toolkit

    King Phisher is an open source tool that can simulate real world phishing attacks. It has an easy-to-use, flexible architecture that allows for full control over both emails and server content. It is useful for running awareness campaigns and training, and can only be used for legal applications when the explicit permission of the targeted organization has been obtained.
    Downloads: 36 This Week
    Last Update:
    See Project
  • 12
    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: 690 This Week
    Last Update:
    See Project
  • 13
    DavMail POP/IMAP/SMTP/Caldav to Exchange
    Ever wanted to get rid of Outlook ? DavMail is a POP/IMAP/SMTP/Caldav/Carddav/LDAP gateway allowing users to use any mail client with Exchange and Office 365, even from the internet through Outlook Web Access on any platform, tested on MacOSX, Linux and Windows
    Leader badge
    Downloads: 615 This Week
    Last Update:
    See Project
  • 14
    Outlook CalDav Synchronizer

    Outlook CalDav Synchronizer

    Sync Outlook with Google, SOGo or any other CalDAV / CardDAV server

    Free Outlook Plugin, which synchronizes events, tasks and contacts between Outlook and Google, SOGo, NextCloud, Horde or any other CalDAV or CardDAV server. Supported Outlook versions are 2021, 2019, 2016, 2013, 2010 and 2007 and Office 365 for Desktop. This project was initially developed as a master thesis project at the University of Applied Sciences Technikum Wien, Software Engineering Degree program. Outlook CalDav Synchronizer is Free and Open-Source Software (FOSS), still you can support the project by donating on Sourceforge or directly within the About dialog of our Plugin. Contact us for enterprise support at https://caldavsynchronizer.org/enterprise/contact
    Leader badge
    Downloads: 582 This Week
    Last Update:
    See Project
  • 15
    SwithMail
    Send SMTP email silently from command line (CLI), or a batch file using Exchange, Gmail, Hotmail, or Yahoo! Plus. Supports XML settings files, variables, or all settings explicitly from the command line. Now supporting Exit Codes for batch file use (will return "0" for successful delivery, or "1" for error delivering) - handle your batch file accordingly.
    Leader badge
    Downloads: 484 This Week
    Last Update:
    See Project
  • 16
    GO Contact Sync Mod

    GO Contact Sync Mod

    Sync Outlook contacts and calendars with Google

    Please install the latest version >4.0, because it uses the new Google People API. The Google Contacts API is now deprecated and is scheduled for sunset on June 15, 2021. GO Contact Sync Mod synchronizes your Microsoft Outlook contacts with your Google Mail address book, including pictures, categories and contact notes. It also syncs your Outlook Calendar Appointments on demand to Google Calendar. This Mod fork adds many enhancements and bug fixes to the obviously dead project 'Go Contact Sync'. Minimum requirement for GO Contact Sync Mod is .NET 4.7.2 and Windows 7 (32 or 64 bit).
    Leader badge
    Downloads: 397 This Week
    Last Update:
    See Project
  • 17
    The Courier mail transfer agent (MTA) is an integrated mail/groupware server based on open commodity protocols such as ESMTP, IMAP, POP3, LDAP, SSL, and HTTP. Courier provides ESMTP, IMAP, POP3, Webmail, calendaring, and mailing list services.
    Leader badge
    Downloads: 348 This Week
    Last Update:
    See Project
  • 18
    MsgViewer
    MsgViewer is email-viewer utility for .msg e-mail messages, implemented in pure Java. MsgViewer works on Windows/Linux/Mac Platforms. Also provides a java api to read mail messges (msg files) programmatically.
    Leader badge
    Downloads: 417 This Week
    Last Update:
    See Project
  • 19
    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: 15 This Week
    Last Update:
    See Project
  • 20
    Elastix

    Elastix

    Unified Communications Server

    Elastix is a software-based PBX powered by 3CX and based on Debian. An open-standards solution, Elastix is an easy to install and manage UC system compatible with popular IP phones, gateways and SIP trunks. Elastix is complete with unified communications features such as integrated WebRTC video conferencing, chat, presence and softphones and smartphone clients for Windows, Mac, iOS and Android.
    Leader badge
    Downloads: 333 This Week
    Last Update:
    See Project
  • 21
    E-MailRelay

    E-MailRelay

    SMTP email proxy and relay server

    E-MailRelay is a simple SMTP proxy and relay MTA, written in C++, for Linux and Windows. As a proxy all messages can be passed through a user-defined program, such as a spam-filter, which can drop, readdress, or edit messages as they pass through.
    Leader badge
    Downloads: 323 This Week
    Last Update:
    See Project
  • 22

    mailsend

    A program to send mail via SMTP from command line

    mailsend is a simple command line program to send mail via SMTP protocol. It can send a piece of alert mail from a program in a networked Windows machine. It's feature-filled, cross-platform, free and open source, and does not use any config file.
    Downloads: 14 This Week
    Last Update:
    See Project
  • 23
    phpList

    phpList

    Powerful Open Source Email Marketing app with analytics & segmentation

    phpList delivers Open Source email marketing, including analytics, list segmentation, content personalisaton and bounce processing. Extensive technical features and a secure and stable codebase are the result of over 17 years of continuous development. Used in 95 countries, available in 20+ languages, and used to send 25 billion email campaigns last year. Deploy it with your own SMTP server, or get a free hosted account at http://phplist.com.
    Leader badge
    Downloads: 320 This Week
    Last Update:
    See Project
  • 24
    trixbox CE is an easy to install, VOIP phone system based on the Asterisk PBX. trixbox is designed for home or office use. trixbox CE includes CentOS linux, mysql, and all the tools needed to run a business quality phone system. (formerly asterisk@home)
    Leader badge
    Downloads: 241 This Week
    Last Update:
    See Project
  • 25
    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 a good mail server easy, promote decentralization, innovation, and privacy on the web, have automated, auditable, and idempotent configuration, not make a totally unhackable, NSA-proof server, and not make something customizable by power users. Mail-in-a-Box turns a fresh Ubuntu 18.04 LTS 64-bit machine into a working mail server by installing and configuring various components. It is a one-click email appliance. There are no user-configurable setup options. It "just works."
    Downloads: 10 This Week
    Last Update:
    See Project
  • Previous
  • You're on page 1
  • 2
  • 3
  • 4
  • 5
  • Next

Open Source Email Software Guide

Open source email software is software that has been made freely available for the public to use and modify, often at no cost. Open source email programs include those created with open source programming languages such as Linux, Apache, and MySQL. The most common type of open source email software is webmail, which provides a graphical user interface for users to send and receive internet mail. Other types of open source email programs include desktop clients like Outlook Express, Eudora, or Thunderbird and server-based systems like Postfix or Courier IMAP. These systems provide more flexibility in terms of features and customization than webmail but require significant technical know-how and are typically used by large organizations.

One of the advantages of using open source email programs is that they support more protocols than proprietary counterparts; this allows users to access their emails across different devices, networks and applications. Additionally, since open source code is publically available it can be studied in detail by developers who can then suggest improvements or create additional features based on their findings. For these reasons many businesses prefer to host their own mail servers rather than rely upon third party services — a task that often requires an open source mail program as a platform for implementation.

Despite being free to use there are some downsides associated with using open source email programs; since the codes aren't typically audited outside of its community there's the potential for security vulnerabilities to exist due to lack of thorough testing prior to releasing an update. Furthermore user support may be limited depending on the size of its user base meaning it could take longer to get any help if encountered with an issue while setting up or configuring your system — something you might expect from paid services not found here.

What Features Does Open Source Email Software Provide?

  • Message Filtering: This feature allows users to set up rules and filters that automatically sort incoming emails into designated folders or take certain actions, like marking, deleting, or forwarding emails to specific addresses.
  • Spam Control: Many open source solutions come with spam control capabilities that can help protect the user from unsolicited emails. These tools can be effective at identifying and blocking spam messages before they reach the inbox.
  • Email Organization: This feature helps organize the user’s mailbox by sorting emails according to sender, date sent, size, subject line, etc. The organization of email will also make it easier for users to search for specific messages in their archive.
  • Security Enhancements: Open source solutions provide enhanced security measures like encryption capabilities and two-factor authentication to ensure that user accounts remain secure from outside threats. Some even offer virus scanning before downloading attachments.
  • Server Integration: Most open source software is capable of integration with different types of servers such as POP3/IMAP4 and Exchange servers so that users can access their account from various locations using any compatible device or client application.

Types of Open Source Email Software

  • eMailing clients: These open source email software applications are designed to allow users to send and receive emails, manage contacts, and create messages. They typically include features such as address book, calendar integration, message filtering, spam detection, encryption/decryption support, and more.
  • Web-Based Clients: These applications usually provide similar features to those of an emailing client but they are hosted on a web server instead of the user's machine. This allows users to access their mail from any computer with a web browser rather than only from one specific computer with an installed mail program.
  • Listservers: These open source email software packages are designed for managing large mailing lists. They can automatically add/remove list members when needed and also handle sending out bulk emails or newsletters in an efficient manner.
  • Email Filtering Software: This type of open source software is designed to filter out unwanted or malicious emails before they reach a user's inbox. The filtering process can be based on keywords, content types, sender information, etc., and this type of software often includes additional security measures such as virus scanning and spam identification.
  • Email Automation Software: This type of application makes it easy for users to automate certain tasks related to email management such as creating new messages based on templates or triggers or forwarding certain messages automatically after certain conditions have been met.

What Are the Advantages Provided by Open Source Email Software?

  1. Accessibility: Open source email systems are free, so they are accessible to anyone with an internet connection or device. This allows users worldwide to take advantage of the features and send emails to clients, colleagues, friends, and family.
  2. Customization & Flexibility: With open source email software, users have the ability to customize their experience as their needs change. They can tailor their system and add features that suit their particular workflow.
  3. Security: Open-source email software is typically more secure than popular web-based services like Gmail or Yahoo Mail because it typically has tightly controlled security protocols in place which prevent malicious actors from infiltrating the system.
  4. Versatility: Open source software can be used on multiple devices - from smartphones to tablets - and can be integrated with other online applications for further versatility. It also allows users to access data offline when necessary.
  5. Cost Savings: Because open source software does not require upfront cost investment such as licensing fees or IT maintenance contracts, businesses can save hundreds of dollars each year that would otherwise go toward purchasing proprietary programs and supporting them throughout their lifespan.

Who Uses Open Source Email Software?

  • Businesses: Businesses often utilize open source email software in order to minimize cost while still having a reliable and secure way of exchanging emails.
  • Organizations: Non-profit organizations often rely on open source software for its cost efficiency and configurability.
  • Individuals: Individuals may use open source email software out of personal preference or because they are unable to afford traditional commercial email solutions.
  • Schools: Schools often turn to open source solutions as they can be configured easily and do not require large budgets.
  • Governments: Governments need secure and efficient communication tools, so many choose open source options as they are usually more secure than their commercial counterparts.
  • Developers/Programmers: Open-source software is a great resource for developers, providing them with an economical option when creating new applications and features.

How Much Does Open Source Email Software Cost?

Open source email software typically does not cost anything. Such programs are generally available for download at no charge, with the source code being open to the public. This means that anyone can take the code, modify it as they see fit, and share it with others. Open source software provides a great opportunity for businesses to save money when selecting an email solution because there is no initial purchase price nor any licensing fees for using them. Additionally, since open source software often has more active development and comes with a larger user community than most commercial offerings, users may find that open source solutions tend to be more reliable and feature-rich in comparison. With this being said, some top-tier features of commercial email platforms may not be available from open source counterparts; however, these types of advanced features usually carry an additional cost regardless of which platform you are using.

What Does Open Source Email Software Integrate With?

Open source email software can integrate with a variety of different types of software. For example, calendar and contact management tools, cloud storage services such as Dropbox or Google Drive, document writing and editing programs like Microsoft Office or OpenOffice, as well as website builders like WordPress can all integrate with open source email software. Additionally, task tracking and project management solutions such as Asana and Trello are often compatible with open source emails. These third-party programs can be used to further enhance the capabilities of the open source email system.

Trends Related to Open Source Email Software

  1. Open source email software is becoming increasingly popular due to its flexibility and affordability.
  2. It is being used by both small businesses and large enterprises, as it offers an efficient way to manage communications.
  3. Open source software allows users to customize the features to suit their needs. This provides greater control over their email solutions, allowing them to tailor their experience to their specific requirements.
  4. Open source platforms are often more secure than other solutions, making them ideal for those who are concerned about data security.
  5. They are also generally easier to set up and maintain. They can be quickly implemented, and any changes or upgrades can be handled quickly and easily.
  6. Open source programs also tend to be more cost-effective than other solutions, making them attractive for businesses on a budget.
  7. Additionally, open source programs have the ability to integrate with existing systems, streamlining email management for businesses that already have existing systems in place.

Getting Started With Open Source Email Software

Getting started with using open source email software is a great way to gain access to powerful and cost-effective email services. Open source tools are used by many people around the world, and are often preferred due to the flexibility they offer in terms of customization options.

The first step to getting started with open source email software is to find an alternativemail client that will suit your needs. Popular open source clients include Thunderbird, Evolution, Clover Mail, and Horde Groupware Webmail Edition. It's important to do some research into each one before you decide which one you'd like to use - this will allow you to determine which features best fit your needs.

Once you've chosen an open source client, you'll need to setup an account by creating a username and password as well as setting up any other required settings such as server information. After configuring all of the necessary settings for your mail client, it's important that you test it out with sending a few emails back and forth between yourself so that you can ensure that everything is working correctly.

After setting up your initial account configuration, it's important that you take some time familiarizing yourself with the user interface if the particular software includes one - this can help make sure that all of its features are properly utilized when sending emails or managing contacts lists. Additionally, users should check if there are any resources available from either the provider or other third-party sources; these could be helpful in understanding additional features or troubleshooting specific problems with their mail client.

Finally, keeping your mail client secure should be given priority; users should enable two-factor authentication at least for their accounts so as not to risk their personal data being hacked or compromised easily. Regularly checking for updates for the particular software along with making regular backups of any data (such as contact lists) stored on it will also help keep safe from unwanted intrusion attempts from malicious actors online. With some basic knowledge of open source email clients and proper maintenance steps taken regularly, users can safely utilize these powerful tools without worrying about security issues caused by lack of carelessness in regards to online safety procedures.