Roundcube - Free webmail for the masses. Roundcube webmail is a browser-based multilingual IMAP client with an application-like user interface. It provides full functionality you expect from an e-mail client, including MIME support, address book, folder manipulation, message searching and spell checking.
Available in over 70 languages
Drag-&-drop message management
Full support for MIME and HTML messages
Sophisticated privacy protection
Compose messages with attachments
Multiple sender identities
Full featured address book with groups and LDAP connectors