I have a SharePoint 2010 environment where I am unable to open .mht files in my browser. Every time reference the .mht file using a page viewer web part or a content editor web part (with iframe) I am shown a prompt to save the .mht file to disk.
I have already set the Browser File Handling to Permissive for the web application.
The Browser I am using is Internet Explorer 9. Might this be causing the problem? In a virtual machine using Internet Explorer 8 I am not confronted with this prompt.
How can I make sure .mht files are opened in the browser window itself instead of receiving a prompt to save to disk.