Roundcube
Overview
Roundcube is a free and open-source web-based IMAP email client written in PHP. It provides a modern, user-friendly webmail interface that feels and behaves like a desktop email application, with full AJAX support throughout. Roundcube is one of the most widely deployed webmail solutions in the world, powering email interfaces for hosting providers, universities, and organisations. It is designed to be lightweight, extensible through plugins, and compatible with any standard IMAP server. The software is licensed under the GNU General Public License v3 (with exceptions for skins and plugins).
Key Features
- AJAX-Powered Interface: Fast, desktop-like user experience with drag-and-drop, inline replies, and smooth navigation.
- IMAP Compatibility: Works with any standard IMAP server, supporting all major providers and self-hosted setups.
- Address Book: Full contact management with LDAP, CardDAV, and CSV import support.
- HTML Composition: WYSIWYG HTML editor for composing formatted emails with attachments.
- Message Management: Search, sort, filter, flag, and organise messages with folder management.
- Spell Checking: Built-in spell checker integrated into the compose interface.
- Plug-in Architecture: Extensive plugin system for calendars (CalDAV), identities, virtual cards, and more.
- Multi-Language Support: Fully localised interface supporting 80+ languages.
- Security: Support for SSL/TLS connections, PGP encryption via plugins, and XSS protection.
- Themes & Skins: Customisable interface with multiple themes including a responsive Elastic skin for mobile devices.
Why Use It
Roundcube is the gold standard for self-hosted webmail. It transforms any standard IMAP server into a capable webmail interface without requiring proprietary protocols or services. Its plugin architecture makes it extensible for calendars, contacts synchronisation, and custom authentication. For hosting providers and organisations, Roundcube provides a reliable, familiar webmail interface that their users can access from any browser without installing software. The Elastic responsive theme ensures a consistent experience across desktop and mobile browsers.
Use Cases
- Web Hosting Providers: Standard webmail interface bundled with hosting packages for customer email access.
- Organisations & Businesses: Self-hosted webmail for employees who need browser-based email access.
- Educational Institutions: Reliable webmail interface for students and staff across multiple devices.
- Privacy-Conscious Hosting: Self-hosted email access without relying on third-party webmail providers.
Platforms
Web (PHP/MySQL/PostgreSQL/SQLite + IMAP server)
Licence
GNU General Public License v3 (with exceptions for skins and plugins)