What do you call private and public boxes where letters are put?
According to Cambridge dictionary, in US, a `mailbox` is a box outside a person's house where letters are put, but in UK, it's a box in the street or other public place in which you can put letters to be collected and sent.
The dictionary states that `postbox` has the same meaning as the second meaning of mailbox (a public box) without mentioning US or UK usages. I could also find the word `letterbox` in the dictionary which seems to be used mostly in UK meaning both a `mail slot` and a postbox. According to the dictionary, *mail slot* is used in US to mean a rectangular hole in the door or in a wall near the entrance of a house or other building, through which letters, etc. are delivered. As a non-native speaker of English, I have these questions.
**1.** Can I use *postbox* safely to mean a public box for letters in UK, US and Australia?
**2.** What word(s) can be used in UK to mean the private box for letter outside your house?
**3.** Is there any word/words that you can use to mean the private box for letter outside your house without ambiguity in UK, US and Australia?
**4.** Can I also use *mail slot* in UK to mean *letterbox*?
**5.** Do you have any other suggestions?
I cannot speak for the UK but in the USA a mailbox is the place outside a home with the little flag to receive and send mail. Look up an image on the Internet if you are confused. Use post office box for the secure box located in a post office or secure facility. This is the P.O Box on an envelope ands is designated with a number. In casual or colloquial conversation a mailbox is anything that receives mail and this includes all manner of mail receptacles in urban high-rises or rural boxes at the end of roads. A mail slot is just as it sounds, any place with a slot in the door for mail. That's it. Don't use any other name in the US. If you're writing a story you can be more specific and can Google the proper name.
