Last Modified 2011-03-29 by Jan Schneider

Release Notes for IMP 5 Alpha 1

The Horde Team is pleased to announce the first alpha release of the Internet Mail Program (IMP) H4 version 5.0.


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.


IMPORTANT! This is a preview version that should not be used on production systems. This version is considered feature complete but there are likely to be bugs. You should not use this preview version with existing production data. Migration of data from earlier versions has not been fully tested yet and is not supported.

We encourage widespread testing and feedback via the mailing lists or our bug tracking system. Updated translations are very welcome, though some strings might still change before the release candidates are prepared.


To install IMP, you need to install Horde first. See https://github.com/horde/horde/blob/master/horde/docs/INSTALL for details. Once Horde is installed, you can install IMP with the following command:

pear install horde/imp-alpha

Then log in to Horde with your adminstrator account to configure the application and install the database schema from the configuration interface.


The major changes compared to the IMP version H3 (4.3) are:

  • Updated for Horde 4
  • All interfaces in a single application
  • New mobile frontend
  • Much improved AJAX frontend including a vertical pane layout
  • New IMAP library written from scratch with broad RFC support and huge performance improvements
  • More powerful search and filter functionality
  • Smart-reply feature
  • Localized special folders
  • Better display of HTML messages
  • HTML signatures
  • Draft auto-saving
  • Support for custom IMAP flags
  • Reduced memory usage