HTTPS/SSL and MIME Types

Changing the MIME type for download of data grid as excel works well in HTTP, but when published in HTTPS, doesnt seem to work in Internet Explorer.

This is because the SSL by default adds the following headers
Pragma: no-cache
Cache-control: no-cache,max-age=0,must-revalidate

Due to these headers, the download does not work in IE, but works with Firefox.

http://support.microsoft.com/default.aspx?scid=kb;en-us;316431

To ensure that your code works in HTTPS/SSL also add the following code

Response.AddHeader("Pragma", "cache")

Check if your code works after adding this, if it is not working still then

go to IE Tools -> Internet options -> Advanced -> Security

uncheck the option "Do not save encrypted pages to disk" and try your code.