UnMHT helps you save webpage into single file as MHT (MHTML, RFC2557) format, and view saved MHT files. UnMHT extension allows you to save and view MHT file.Note: The UnMHT add-on is cross-platform and it works on Mac OS X, Windows and Linux.Requirements:

Ссылка: http://releases..b/mozilla.org/addons/8051/unmht-5.2.0.1-fx.xpi