Roundcube

What Roundcube is

Roundcube is a browser-based, multilingual IMAP client that email providers and administrators install on their own servers. It is not an email service that supplies user accounts. Its application-like interface handles MIME and HTML messages, multiple sender identities, threaded listings, search, and spell checking. The address book supports groups and LDAP connections, with find-as-you-type integration. Administrators can customize it through a plug-in API and templates; third-party plugins and skins are available through Packagist. Listed protections and sign-in options include brute-force login prevention, XSS protection, PGP encryption, and OAuth/XOAuth. Roundcube is free, with a listed plan of no cost and unlimited users and messages. Installation requires PHP 8.1 or later, a supported web server, a MySQL/MariaDB, PostgreSQL, or SQLite database, plus SMTP and IMAP servers. It can run as a Docker PHP-FPM service or with a complete Apache webserver. The project provides Docker Compose and Kubernetes examples. It does not provide or recommend native mobile apps.