Is it really illegal for someone who&#39;s not a postman to use a mailslot in the USA?
<p>According to an <a href="https://law.stackexchange.com/questions/6726/is-it-legal-to-film-yourself-putting-something-in-a-mail-slot/6750?noredirect=1#comment12818_6750">answer given here</a> "It is illegal for anyone other than the USPS to put mail in someone's mailbox" From <a href="https://about.usps.com/news/state-releases/tx/2010/tx_2010_0909.htm" rel="nofollow noreferrer">https://about.usps.com/news/state-releases/tx/2010/tx_2010_0909.htm</a></p>

<blockquote>
  <p>By law, a mailbox is intended only for receipt of postage-paid U.S.
  Mail.</p>
</blockquote>

<p>This sure is a strange law. Why was it made? So it's illegal for someone to deliver their own mail in the US? What about non-mail items, like locking the door and putting the key through the mail slot, is this technically illegal in the US?</p>

<p>A mail slot is not a mailbox. So putting a key through a mail slot after locking the door is not the same as putting the key in a mailbox. </p>

<p>It is illegal to use a mailbox, yes.  (Not necessarily a mail slot).  You are looking for 18 USC 1725.</p>

<blockquote>
  <p>Whoever knowingly and willfully deposits any mailable matter such as
  statements of accounts, circulars, sale bills, or other like matter,
  on which no postage has been paid, in any letter box established,
  approved, or accepted by the Postal Service for the receipt or
  delivery of mail matter on any mail route with intent to avoid payment
  of lawful postage thereon, shall for each such offense be fined under
  this title.</p>
</blockquote>

<p><a href="https://www.law.cornell.edu/uscode/text/18/1725?qt-us_code_temp_noupdates=0#qt-us_code_temp_noupdates" rel="nofollow">https://www.law.cornell.edu/uscode/text/18/1725?qt-us_code_temp_noupdates=0#qt-us_code_temp_noupdates</a></p>

<p>As to why the monopoly exists, that's a legislative history question.  There are all of the obvious advantages and disadvantages: network effects, interference with official mail, government income, freedom from spam; inconvenience, making it easier to receive unofficial mail, increased competition in mail delivery, no need for a second mailbox for newspapers, better advertising information from said spam.</p>

united-states mail