PRO EXPORT does not export jpg

Hello, 

I am having some trouble with the PRO EXPORT settings. Despite having set the output details as follows: 

Output file : JPEG

Hide Crop Marks: deactivated

Image DPI: 300 DPI

The file attached to the email order is a PDF. I can't seem to set it as a JPEG.

Is there anywhere else where I should look in order to fix this issue? I should be fairly simple but I cannot seem to fix it.

Any insight would be greatly appreciated!