If you're using Linux as a Desktop system sooner or later you will receive an email with instructions or an html page stored in .mht file format.
So what is mht? MHT is an webpage archive format (short for MIME HTML document). MHTML saves the Web page content and incorporates external resources, such as images, applets, Flash animations and so on, into HTML documents. Usually those .mht files were produced with Microsoft Internet Explorer – saving pages through:
File -> Save As (Save WebPage) dialog saves pages in .MHT.
To open those .mht files on Linux, where Firefox is available add the UNMHT FF Extension to browser. Besides allowing you to view MHT on Linux, whether some customer is requiring a copy of an HTML page in MHT, UNMHT allows you to also save complete web pages, including text and graphics, into a MHT file.
There is also support for Google Chrome browser for MHT opening and saving via a plugin called IETAB. But unfortunately IETAB is not supported in Linux.
Anyways IETAB is worthy to mention here as if your'e a Windows users and you want to browse pages compatible only with Internet Explorer, IETAB will emulates exactly IE by using IE rendering engine in Chrome and supports Active X Controls. IETAB is a great extension for QA (web testers) using Windows for desktop who prefer to not use IE for security reasons. IETab supports IE6, IE7, IE8 and IE9.
Another way to convert .MHT content file into HTML is to use Linux KDE's mhttohtml tool.
Another approach to open .MHT files in Linux is to use Opera browser for Linux which has support for .MHT
Note that because MHT files could be storing potentially malicious content (like embedded Malware) it is always wise when opening MHT on Windows to assure you have scanned the file with Antivirus program. Often mails containing .MHT from unknown recipients are containing viruses or malware. Also links embedded into MHT file could easily expose you to spoof attacks. MHT files are encoded in combination of plain text MIMEs and BASE64 encoding scheme, MHT's mimetype is:
MIME type: message/rfc822