Open Source Linux Email Software
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Email Software for Linux
View 30 business solutionsBrowse free open source Email software and projects for Linux below. Use the toggles on the left to filter open source Email software by OS, license, language, programming language, and project status.
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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 -
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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 24261. 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. -
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Windows MBox Viewer
Windows eml and mbox viewer.
Free Windows Mbox Viewer. Gain access to mbox archives, single eml or single Outlook 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. -
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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. -
Ship Agents FasterGemini Enterprise Agent Platform lets you rapidly build, scale, govern and optimize production-ready agents grounded in your organization's data. The platform enables developers to build custom or pre-built agents for virtually any use case. New customers get $300 in free credits.
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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. -
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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
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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! -
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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. -
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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.
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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. -
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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.
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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. -
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bogofilter -- Fast Bayesian Spam Filter
Fast Bayesian spam filter along lines suggested by Paul Graham
The bogofilter package implements a fast Bayesian spam filter as suggested by Paul Graham in "A Plan For Spam" <http://www.paulgraham.com/spam.html>. It is written in C. Supported platforms: Linux, FreeBSD, Solaris, OS X, HP-UX, AIX, RISC-OS, ... -
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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)
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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. -
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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. -
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Fetchmail - the mail-retrieval daemon
Client daemon to move mail from POP and IMAP to your local computer
Fetchmail is a mail retrieval daemon that can download messages from POP3, IMAP, ODMR and ETRN-based stores, with SSL/TLS security including certificate verification, and pass downloaded mail to a local SMTP or LMTP server, or a message delivery agent such as maildrop. -
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Google Apps Manager
Command line management for Google G Suite
Google Apps Manager or GAM is a free and open source command line tool for Google G Suite Administrators that allows them to manage many aspects of their Google Apps Account quickly and easily. With GAM you can create and manage users, groups and domains; manage email, security and calendar settings; manage admins and organizations and many more. To use GAM Google Apps Business, Education, Partner or Government Edition is required. -
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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.
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Isync
mailbox synchronizer
A command line utility for synchronizing remote IMAP mailboxes and local maildir-style mailboxes. This is useful for working in disconnected (off-line) mode, such as on a laptop, but also for mirroring mailboxes between servers. -
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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. -
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PostfixAdmin is a Web Based Management tool created for Postfix. It is a PHP based application that handles Postfix Style Virtual Domains and Users that are stored in MySQL, PostgreSQL or SQLite
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PHPMailer
A full-featured email creation and transfer class for PHP
A PHP email creation and transport class featuring file attachments, SMTP servers, CCs, BCCs, HTML messages, word wrap, and more. Sends email via sendmail, PHP mail(), QMail, or with SMTP. PHPMailer is used by many popular PHP development frameworks and is one of the most popular email-generating and sending libraries in the world. This project is defunct here on sourceforge – it's now maintained on Github at https://github.com/PHPMailer/PHPMailer. Documentation is available at https://github.com/PHPMailer/PHPMailer/wiki -
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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. It provides a seamless integration layer for users who need offline support, familiar local client workflows, or tighter integration with desktop tools while preserving Proton’s zero-access encryption model. The Bridge app continues running even when its GUI is closed so that mail clients can remain connected and synchronized, and it supports automatic startup and robust credential handling via secure storage.
