There is a good chance this is just a fake letter.
This guy was making them for fun a while back, and they surface from time to time.
I'm pretty sure the dashcam submission system is called Operation Snap, not Capture, too.
Invented English? Nah, mate, nothing homegrown there. We imported it - a strong base if Anglo-Saxon and a dollop of Norman French making it a bit more posh, with shoots of Brythonic, Latin and Old Norse poking through the cracks. All that before we went nicking words from all over the world that took our fancy.
By this pont we barely know how it all works - we're like monkeys driving a monster truck frankensteined together from an ice cream van, a golf cart, a tank and a Postman Pat toy; just mashing the controls hoping to make it go in vaguely the right direction.
By your definition, every language is like that then.
The only "pure" languages are spoken in countries with small populations. And even then they still get external influences, and I doubt it would be spoken as it was 1000/2000/3000 years ago...