I think what you want is only possible with the Mashup Editor in Qlik Sense.
Here you can create your own Website based on Qlik Sense Data.
Another possibility is, that you search in the Qlik Branch for an Extension to show IFrames or HTML Code like:
HTML Box for Sense
Dynamic URL iFrame Window
Or what you need for your Case.
I've looked at the extensions and to me it seems that they are more used to load HTML code with the editor in your sheet.
However, i'm not able to load the data each time via the editor in an sheet, that is because each email is different.
For example, I've more than 100 emails and i need to be able to link the emails to an index so that the user can select in a menu the email.
Then you can use perhaps the Qlik Branch Media Box for Qlik Sense.
I have created a short Testapp by my own.
In my Loadscript:
LOAD * INLINE [
Qlik Branch, 'http://branch.qlik.com/#!/project'