eFax Corporate includes a free, optional, download which enables you to read faxes received as .efx or .tif files. You can also respond to faxes you receive without printing or rescanning them. Simply annotate, sign and return your approval by fax using the eFax Messenger desktop fax software. In addition, eFax Messenger enables you to email web pages, screenshots, and a variety of other file types as self-viewing attachments - the attachment looks and prints just like the original, even in color! eFax Messenger for Windows 2000, XP, or NT - allows eFax Corporate users to create, annotate, and send faxes and email messages. eFax Messenger supports sending for Office 2007, StarOffice and OpenOffice documents. Users can also view, zoom, rotate and print their received faxes, without any advertising in the toolbar of the viewer or in the fax itself. Each user must install the eFax Messenger software on their client PC to utilize these features.