You've paid the Air Mail rate here in Australia so I seriously doubt it's gone by sea mail.
As far as I am aware, letters will go via Air Mail and parcels will be sent via Air Mail or Sea Mail depending on the method of shipping chosen.
Regardless of whether you've written "United Kingdom" or "England", I'm pretty sure at the end of the day it would have eventually reached its destination.
Your request could just be delayed for some reason though 3 weeks is a lot of time.
My guess is that they may have received your request, but:
1. The person replying to your email was not aware that it had been received
2. A bit confused as you didn't include a reply address - he/she may have thought it was from someone else
3. Been mixed in with other mail for that person or has had quite a large volume of mail received that they didn't check
I wouldn't be too worried at this point. Give it a few weeks/months to see if you get a reply. If not, then try it again with your return address on the envelope.
Good luck!
nowandagain

You've paid the Air Mail rate here in Australia so I seriously doubt it's gone by sea mail.
As far as I am aware, letters will go via Air Mail and parcels will be sent via Air Mail or Sea Mail depending on the method of shipping chosen.
Regardless of whether you've written "United Kingdom" or "England", I'm pretty sure at the end of the day it would have eventually reached its destination.
Your request could just be delayed for some reason though 3 weeks is a lot of time.
My guess is that they may have received your request, but:
1. The person replying to your email was not aware that it had been received
2. A bit confused as you didn't include a reply address - he/she may have thought it was from someone else
3. Been mixed in with other mail for that person or has had quite a large volume of mail received that they didn't check
I wouldn't be too worried at this point. Give it a few weeks/months to see if you get a reply. If not, then try it again with your return address on the envelope.
Good luck!
nowandagain :)