Roundcube - Free and Open Source Webmail Software | WarmIndex

Roundcube is a free and open-source browser-based multilingual IMAP client with an application-like user interface, providing full email functionality for self-hosted webmail.

🚀 Overview

Roundcube Webmail is a powerful, browser-based IMAP email client that delivers a desktop-like experience with drag-and-drop, threading, and advanced search capabilities. It supports modern email standards like MIME, HTML rendering, and PGP encryption.

This project solves the need for a customizable, high-performance webmail solution that works with any IMAP server, offering privacy and control over hosted email without vendor lock-in. It's an alternative to commercial webmails like Outlook Web or Gmail for those preferring self-hosting.

Built for web hosting providers, sysadmins, organizations, and anyone managing their own email infrastructure. The open-source community created it to provide extensible, secure webmail that's easy to deploy and theme.

✨ Key Features

Drag-&-drop message management, threaded listing, and responsive multi-device skins
Full MIME/HTML support, spell checking, and PGP encryption
Advanced address book with LDAP/groups, find-as-you-type, and vCard import/export
Plugin API for extensions, shared/global folders, ACL support
Built-in caching, XSS protection, IDNA/SMTPUTF8, unlimited users/messages
Optional: Upcoming 1.7 stable release with new features