Hello; Good Day!
Well I am surprised to see your intentions, dear. Yes, you may be successful in sending a post by puting a fake address.
But, that is NOT ethical at all. If you are inculcating this type of fake and false deeds at your age - I wonder, in near future you will be treated by your friends to be a 'fraud and/or cheat'.
PLZ do not ever think to cheat any person or any organization. this will become a charater trait in your self. I am sure, you want to be highly respected and trusted by all in near future- don't you???
>>>>>>>>>>>
EDIT
Dear Brother/Sister;
Sorry, it is my mistake. I must have just overviewed your narration re BBC story. It was 100% my mistake, in my mind I was in the opinion that you asked if you could post an unstamped envelop with fake address on.
I usually read all Qs thoroughly b4 answering. I don't know dear how I made such a BIG mistake and hurt your feelings. PLZ forgive me dear.
Now, I would say that ONE shouldn't try to send a letter Like Dave suggested. It's cheating the Government - I am sure you will agree with me,
<<<<<<<<<<<<<<<<<
Love and Peace for Mankind