Quoted-Printable content encoding support

While using   getHTMLText() function to convert mht content to html, we are getting the below  error message. 
"Failed to find string 'boundary'"
I found that the issue is, i have converted html to mht by using another program. I there any way to convert html to mht by using your library. if this works, that will more helpful for me.

Please reply as early as possible.
