Email Software for Windows

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Browse free open source Email software and projects for Windows 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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  • 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
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    Downloads: 103,802 This Week
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  • 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 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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    Downloads: 42,118 This Week
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  • 3
    Windows MBox Viewer

    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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    Downloads: 1,457 This Week
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  • 4
    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: 193 This Week
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  • 5
    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).
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    Downloads: 809 This Week
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  • 6
    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.
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    Downloads: 621 This Week
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  • 7
    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
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    Downloads: 546 This Week
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  • 8
    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
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    Downloads: 487 This Week
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  • 9
    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.
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    Downloads: 305 This Week
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  • 10
    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.
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    Downloads: 305 This Week
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  • 11
    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: 64 This Week
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  • 12
    PHPMailer

    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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    Downloads: 175 This Week
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  • 13
    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.
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    Downloads: 137 This Week
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  • 14
    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.
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    Downloads: 154 This Week
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  • 15
    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.
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    Downloads: 139 This Week
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  • 16
    Google Apps Manager

    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.
    Downloads: 25 This Week
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  • 17
    Outlook Mail Merge Attachment is a script which can be used to add an attachment to an mail merge in Microsoft Outlook.
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    Downloads: 145 This Week
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  • 18
    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: 24 This Week
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  • 19
    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: 22 This Week
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  • 20
    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: 20 This Week
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  • 21
    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. The app works on Linux/OSX/Windows platforms. Binary installation packages. Offline access to the email messages (attachments content not stored locally, but emails body content). The local store feature enables storing your messages in the encrypted database.bin file (see FAQ for file purpose details). So the app allows you to view your messages offline, running full-text search against them, exporting them to EML/JSON files. etc. Enabled since v2.0.0 release.
    Downloads: 19 This Week
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  • 22
    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
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  • 23
    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. 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.
    Downloads: 14 This Week
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  • 24

    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: 12 This Week
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  • 25
    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.
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    Downloads: 46 This Week
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