IMP is a completely free, platform-independent and open source web-based application, a plugin for the Horde Groupware suite that provides an individual Internet Messaging Program, which allows users to access IMAP (Internet Message Access Protocol) and POP3 (Post Office Protocol 3) mail servers.
Features at a glance
Key features include multiple views, including dynamic (AJAX), thread view, mobile smartphone, and minimal (text-only), support for HTML signatures, address autocompletion, spell checking, folder subscriptions, flexible message search, support for managing shared IMAP folders via ACLs (Access Control Lists), as well as support for multiple identities.
Among other features implemented in the IMP application, we can mention HTML message composition via a WYSIWYG (What You See Is What You Get) editor, drag and drop attachment support in the WYSIWYG editor, email previews, email filtering, calendar and address book integration, mailbox quotas, message flags, full charset support, and IMAP folder support.
Additionally, the IMP application supports all the advanced functions of IMAP, supports downloading of attachments as ZIP archives, supports stripping of attachments from emails, supports previewing of attachments in the compose view mode, supports forwarding or multiple emails at once, supports PGP and S/MIME-based signatures and encryption for messages.
Getting started with IMP
IMP requires a working Horde installation, at least one POP3 or IMAP server, a SMTP or Sendmail server, as well as a PHP installation with support File Upload and OpenSSL. In addition, you should install the PEAR installer, which will be used for installing IMP.
Simply run the ‘pear install -a -B horde/imp’ command to install IMP with all optional dependencies, or run the ‘pear install horde/imp’ command to install IMP only with the required dependencies, or run the ‘pear install -a horde/imp’ command to install IMP with all binary dependencies. Then, proceed to the initial configuration http://www.horde.org/apps/imp/docs/INSTALL#configuring-imp.