Final answer:
The mailbox rule states that an acceptance of an offer is effective upon dispatch, however, if the offeror has stated that acceptance must be received to be effective, then the mailbox rule does not apply and acceptance is only effective upon receipt.
Step-by-step explanation:
The statement is true. According to the mailbox rule (also known as the posting rule), for contracts formed by correspondence, acceptance takes effect when a letter of acceptance is posted, not when it is received by the offeror. This legal doctrine facilitates the formation of contracts at a distance by deeming the acceptance of an offer effective upon dispatch.
However, it is important to note that the mailbox rule does not apply if the offeror has stipulated that an acceptance must be received to be effective. If such a stipulation is made, the traditional rule is that the acceptance is effective once it has been received by the offeror, not when it is sent by the offeree. This is because the offeror is entitled to dictate the terms under which they are willing to be bound by an acceptance.