Mailbox Rule: Acceptance and Revocation Timing

Answer D. The mailbox rule normally makes an acceptance effective on dispatch, but an offeror can specify that acceptance must be received, which displaces that default. Harper's offer explicitly required receipt by May 10; because Lane's acceptance was not received until May 11, it was ineffective and no contract formed. (Revocations are effective on receipt, not on mailing.)

Why not A: This is tempting because the mailbox rule ordinarily makes a mailed acceptance effective upon dispatch. It fails here because Harper's offer displaced that default by requiring acceptance to be received by May 10, so a mailed acceptance not received by the deadline is ineffective.

Why not B: This distractor is plausible: revocations are ineffective until received, and Harper's revocation was not received before Lane mailed acceptance. It is nonetheless incorrect because the offer's explicit receipt requirement displaces the mailbox rule, meaning a May 9 mailing that was not received by the deadline cannot be treated as an effective acceptance.

Why not C: This answer reaches the same outcome but for the wrong reason. It is tempting if one mistakenly treats revocation as effective on mailing, but revocations generally take effect only upon receipt. The controlling reason here is the offer's receipt requirement plus the late receipt of acceptance.

Answer B. Buyer's $2,000 created an enforceable option that made the offer irrevocable through 5:00 p.m. on March 10. Under prevailing common‑law authority, exercising an option is generally treated as requiring receipt of the acceptance during the option period unless the parties agreed otherwise. Because Buyer's acceptance was not received until March 11, after the option expired, no sales contract was formed.

Why not A: This is tempting because the mailbox rule often makes mailed acceptances effective on dispatch, but that rule is frequently limited for options: many courts require receipt to exercise an option (absent an agreement to the contrary), and here acceptance was received after the option expired.

Why not C: This confuses purchasing an option with acceptance of the underlying contract. Paying for an option obligates the offeror to keep the offer open for the option period; it does not itself constitute acceptance of the sale.

Why not D: This is plausible because Owner attempted to revoke, but an effective option makes the offer irrevocable through its stated time; the attempted revocation during the option period was ineffective, so the decisive fact is that acceptance was not received until after the option expired.

Answer A. Under common law the mailbox rule generally makes an acceptance effective on dispatch, but when the offeree sends a rejection first and then an acceptance, whichever communication is received first controls. Because Owner received the acceptance on June 6 before receiving the rejection on June 7, a contract was formed on June 6.

Why not B: This mistakes the general dispatch rule for acceptances as always controlling. That rule is limited here because Contractor had already mailed a rejection; when a rejection is sent first the later acceptance is effective only if it arrives before the rejection.

Why not C: A rejection is generally effective on receipt, not on dispatch. Since Owner did not receive the rejection until June 7 and had already received the acceptance on June 6, the mailed rejection did not prevent formation.

Why not D: While a promise to hold an offer open is not binding at common law without consideration, that only means the offeror could revoke prior to acceptance. Here Owner did not revoke and received a valid acceptance before receiving the rejection, so lack of consideration for the option does not prevent contract formation.

Answer A. When an offeree sends a rejection and later sends an acceptance, the usual dispatch rule is displaced by the rule that the first communication received by the offeror controls. Because Seller received Buyer's acceptance on June 6 and did not receive the earlier rejection until June 7, the acceptance prevailed and a contract was formed on June 6.

Why not B: This is tempting because acceptances are often effective on dispatch, but that general rule is qualified when the offeree previously mailed a rejection. If a rejection is mailed first, the timing of receipt controls, so the acceptance did not prevail on dispatch here.

Why not C: Rejections (and revocations) are generally effective on receipt, not on dispatch. Because Seller received the acceptance before receiving the rejection, the acceptance took effect first and formed the contract.

Why not D: Although a promise to keep an offer open is not binding without consideration (absent an option or other exception), Seller never revoked the offer. The controlling question is the timing of the communications; because Seller received the acceptance before the rejection, a contract resulted.

Answer D. An offeror may prescribe an exclusive manner and timing for acceptance. Here, Gray's offer expressly required receipt of a signed acceptance email by the stated deadline and stated no other method would be effective; because Lane never sent that required email, no binding contract was formed.

Why not A: Oral acceptance can be sufficient in many settings, but here the offer expressly rejected other methods and required a signed acceptance email received by the deadline, so a voicemail alone would not create a contract.

Why not B: Tempting because if an offer is silent about method, acceptance by a reasonable means is often allowed. It's wrong here because the offer did not leave the method open; it made receipt of a signed acceptance email the exclusive effective method.

Why not C: This plays on the mailbox (dispatch) rule, which can make mailed acceptances effective on dispatch. But that default rule is displaced when an offer specifies a required method or requires receipt by a deadline.