Subject: Protocol, Royal Protocol
If you want to get your letter past the staff and into her Majesty's in-tray you should follow the rules laid out below. There are still no guarantees that she will see your letter, but if you don't follow the rules of palace protocol it is a good bet that she won't see the letter.
Firstly you need an address to send letters to. The Queen of England does not have an email address (at least none that the general public get to hear of).
Her Majesty The Queen
London SW1A 1AA
Place the address on both the envelope and at the top of the letter
The only correct way to start a letter to the queen is with "Madam" not Dear Madam, Dear Queen, Elizabeth or any other begining.
When talking about her always use the term "your Majesty" rather than 'you'
End your letter as follows:
"I have the honour to remain
Your Majesty's most humble and obedient servant"
then sign your signature.
You should also make sure your handwriting is legible.