You can actually put the resize code in yourself.
When using the img src= HTML tag, after the second “ at the end of the images address, put in width=800 before the closing >
Like I said, the FR code should do that automatically. If a width isn’t specified and the image is wider than 800, or the specified width is more than 800, then the FR posting code should automatically insert a maximum. They have quite a bit of error-checking code built in for other things, like checking the URL you are posting to see if it requires excerpting.