Top 20 open-source products relevant to Email Clients

Spark helps you take your inbox under control. Instantly see what’s important and quickly clean up the rest. Spark for Teams allows you to create, discuss, and share email with your colleagues.

Open Source

Get your encrypted mailbox for free.

Open Source

Mailspring is a mail client for Mac, Windows and Linux.

Open Source

Mail-in-a-Box provides webmail and an IMAP/SMTP server for use with mobile devices and desktop mail software and also includes contacts and calendar synchronization.

Open Source

Web-based IMAP email client.

Open Source

A fully fledged, free email server solution, an open source project (GPL v2).

Open Source

Mailpile is a modern, fast web-mail client with user-friendly encryption and privacy features.

Open Source

Open source, privacy friendly email app.

Open Source

RainLoop is a web based email client.

Open Source

An email client that works like a kanban board.

Open Source paid Free Trial $45.0 / One-off (Limited time v1 license)

SOGo is groupware server with a focus on scalability and open standards.

Open Source

All your E-mail, from all your accounts, in one place. Cypht is like a news reader, but for E-mail.

Open Source

💌 Mail app for Nextcloud.

Open Source

Cal and CardDAV server.

Open Source

Criptext - Security that goes beyond encryption.

Open Source

NeoMutt is a command-line mail reader. It's a version of https://alternativeto.

Open Source

OpenSMTPD is a FREE implementation of the server-side SMTP protocol as defined by RFC 5321, with...

Open Source

The Radicale Project is a complete CalDAV (calendar) and CardDAV (contact) server solution.

Open Source

sendEmail is a lightweight, command line SMTP email client.

Open Source

Free utility to send emails from the command line. No Installation. All contained in one file.

Open Source