When does acceptance take effect? The mailbox rule, and silence

England, September of eighteen eighteen.  Two wool dealers write to a manufacturer offering to sell him wool, and they ask for an answer in course of post.  They put the wrong address on the letter.  It wanders, and reaches him on the fifth of the month instead of the third.  He accepts by return post the same day.  His letter reaches the dealers on the ninth.
But on the eighth, having heard nothing by the seventh when they expected to, they sold the wool to someone else.
So here is the question, and it is older than the railway. When the manufacturer dropped his acceptance in the post on the fifth, was there a contract? Or was there no contract until the dealers opened it on the ninth, by which time the wool was gone? Think about it before I go on, because a rule that has run for two hundred years came out of that letter.
The question I keep asking. What exactly did these people promise each other? The dealers offered, and asked for an answer by post. The manufacturer answered by post. If the dealers chose the post, who bears the risk of the days the letter spends in it?
First line for the board. Unless the offer says otherwise, an acceptance sent by a medium the offer invites takes effect the moment it leaves the offeree's hands. In the mail, that is the moment of posting. This is called the mailbox rule. Second line. Everything else is different. A rejection takes effect when it arrives. A revocation takes effect when it arrives. Only acceptance is special, and only because the offeror invited that way of answering.
Third line.  Why?  The English court gave the reason in eighteen eighteen, and no one has improved on it.  Here it is, as the Florida court quoted it more than a century later.  If the defendants were not bound by their offer when accepted by the plaintiffs till the answer was received, then the plaintiffs ought not to be bound till after they had received the notification that the defendants had received their answer and assented to it.
And so it might go on ad infinitum.
The court's solution was to say that the offeror, having chosen the post, is treated as repeating his offer every moment the letter travels. In the court's words, the defendants must be considered in law as making, during every instant of the time their letter was traveling, the same identical offer to the plaintiffs, and then the contract is completed by the acceptance of it by the latter. The line has to be drawn somewhere. The law draws it at posting.
Now the American case, which is where the rule was tested against a telephone.  Florida, nineteen fifty seven.  Buyers signed a contract to purchase land in Orange County and mailed it to the sellers, who were out of state.  The sellers signed it and mailed it back to the buyers' lawyer in Florida.  Then, before the letter arrived, the sellers telephoned the lawyer and said they were cancelling.
The trial court held for the sellers, on the ground that the contract had been repudiated before it was received.
The District Court of Appeal reversed.  It framed the question this way.  Whether a contract is complete and binding when a letter of acceptance is mailed, thus barring repudiation prior to delivery to the offeror, or when the letter of acceptance is received, thus permitting repudiation prior to receipt.  And it answered with the rule.
If acceptance by mail is authorized, the contract is completed at the moment the acceptor deposits in the post office the letter of acceptance directed to the offerer's proper address and with the postage prepaid.
The court did not pretend the rule is perfect. It quoted the old observation that a complete, final, and absolutely binding contract is formed as soon as the acceptance of an offer is posted may in some cases lead to inconvenience and hardship. It kept the rule anyway, because certainty is what a rule of formation is for. The sellers' telephone call came after the letter was in the mail. The contract already existed. The call could not undo it.
Now a different way of accepting, or failing to. Massachusetts, eighteen ninety three. A man sends eel skins to a whip company. He has done it four or five times before, and each time the company took them and paid. This time the company says nothing, keeps the skins for months, and lets them be destroyed. He sues for the price. The company says it never accepted anything. It just did not answer.
Justice Holmes, for the court, held for the seller.  The rule you need is this.  Silence is not acceptance.  Nobody can make you a party to a contract by sending you something and daring you to refuse.  But there are exceptions, and this was one.  Here is the court.
In such a condition of things, the plaintiff was warranted in sending the defendant skins conforming to the requirements, and even if the offer was not such that the contract was made as soon as skins corresponding to its terms were sent, sending them did impose on the defendant a duty to act about them.
The prior dealings made the difference.  After four or five deliveries accepted and paid for, silence in the face of the next one reasonably meant yes, and the company, which knew that, had a duty to speak if it meant no.  So put it on the board as the fourth line.
Silence accepts only where the offeree takes the benefit of what was offered with a chance to refuse it, or where prior dealings make silence reasonably understood as assent, or where the offer says silence will accept and the offeree, by staying silent, means it to.
Now let's change one fact. A buyer mails an acceptance on Monday. On Tuesday the seller telephones to revoke. Contract? Choose an answer before I go on.
Most people say yes, and they are right. The acceptance took effect on Monday, when it was posted. Tuesday's revocation arrived after the contract already existed, so it revoked nothing. This is the Florida case with the roles reversed, and it comes out the same way.
Change one fact again. The buyer mails a rejection on Monday. On Tuesday he changes his mind and sends an acceptance by overnight courier, which arrives Wednesday morning. The rejection arrives Wednesday afternoon. Contract? Choose.
Most people say no, because the rejection was sent first.  But rejections are not special.  They take effect on arrival, not on sending.  Where a rejection and an acceptance are both in transit, the acceptance operates only if it arrives first.  Here it did.  Contract.  Now reverse the arrival times, rejection first, and there is none.  The question is never which was sent first.
It is which arrived first, because the rule protects the offeror from being bound by a letter he has not seen after one he has.
Change one fact a third time. The buyer mails an acceptance on Monday. On Tuesday he telephones and says, ignore that letter. The seller, relying on the call, sells the goods to someone else on Wednesday. Thursday the letter arrives and the buyer sues. Choose.
This one is argued, and I want you to see both halves.  Under the mailbox rule the contract formed on Monday, so the buyer has a contract.  But the buyer then told the seller to ignore it, and the seller relied on that to his cost.  Most courts would not let the buyer enforce a contract he had himself disowned in a way the seller relied on.  The honest answer is, a contract, and an estoppel that stops the buyer from using it.
Say both, in that order.
Here is what people get wrong here, and why it is tempting.  The first mistake is applying the mailbox rule to everything that travels by post.  It applies to acceptance, and nothing else.  Rejections and revocations arrive.  The second mistake is forgetting that the offeror can switch the rule off.  An offer that says, acceptance is effective only when I receive it, means what it says.  The third mistake is the silence trap.
Silence is not acceptance, and then a student remembers the eel skins and swings too far.  The eel skins were the exception, and it took four or five prior deliveries to make it.
Here is the rule, in one breath. An invited acceptance takes effect when it is sent, a rejection or revocation when it arrives, an acceptance sent after a rejection only if it arrives first, and silence accepts nothing unless the offeree takes the benefit, prior dealings make silence assent, or the offer says so and the offeree means it. Now, five questions.