Beauregard. I'm glad you asked this. To submit a script, screenplay, idea and so on to a production company you would need to go through a registered agent. Any unsolicited material is returned or destroyed, unopened.
As an aside. Same goes for any ideas posted on forums or websites. No Henson person would look at them for fear of being sued. Almost nobody steals ideas in Hollywood. And it would never happen at Henson. But posting sketch and ideas or scripts in public places is a virtual guarantee that those ideas will never happen. Even if the writers came up with them independently, if it's already been published online or someplace by someone else, they wouldn't do it for legal reasons.
I don't mean that for you personally Beau. Just a word of advice for anybody around here. The only way to submit an idea is through an agent. There are plenty of books on writers' marketplaces, selling screenplays and so on available.
secret squirrel