Pangolin,
Are you referring to the official Amazon "Send to Kindle" extension, or is this a third-party product?
The reason I ask is that the official Amazon product has earned an awful lot of bad reviews (for the Firefox version). See
https://addons.mozilla.org/en-US/fir...views/?src=api
I haven't tried it myself yet, and I'm not doubting your word. I just wondered if it was the same product.
At present, I use Pocket, which is good for sending stuff to my Android tablet, but it doesn't directly support the physical Kindle (as far as I know).
Mike