IMP, the Internet Mail Program, is one of the most popular and widely deployed open source webmail applications in the world. It allows universal, web-based access to IMAP and POP3 mail servers and provides Ajax, mobile and traditional interfaces with a rich range of features normally found only in desktop email clients.

This package is part of Horde, a web application Framework written in PHP with modules like IMP (webmail), Turba (contacts), Kronolith (calendar), Nag (task list), Gollem (file manager), etc.