5 The mailbox rule specifies that no one other than the Postal Service (and the addressee) may put mail into the box.
The mailbox rule was put in place to discourage unsolicited mail.
mnli hypothesis: The mailbox rule was put in place to discourage unsolicited mail. premise: 5 The mailbox rule specifies that no one other than the Postal Service (and the addressee) may put mail into the box.