You can't. If you try you will be breaking the law, and it is illegal for the mailman to give it back to you once he opens the box.
yes put the flag up so he knows its there
I am not sure what you are asking. If you mail a letter to yourself you will get your letter just like the rest of the mail. The mailman knows because he puts the letter in your mailbox.
A seven letter word with a thousand letters in it would be: a mailbox.
mailbox
mailbox
mailbox
Mailbox
mailbox
My brother's mailbox in Netanya.
Mailbox
chute
In a mailbox.