A supplier of flour who intends to sign a contract with a baker through post can establish a binding agreement only

In order to establish a binding agreement between a supplier of flour and a baker through post, the following things need to happen: 1. The offeror (in this case, the supplier of flour) needs to make an offer in writing and send it to the offeree (in this case, the baker). 2. The offeror's letter needs to reach the offeree. This means that the letter needs to be delivered to the offeree's address. 3. The offeree needs to post their acceptance of the offer back to the offeror. 4. Once the offeror receives the offeree's letter of acceptance, a binding agreement is established. Therefore, the answer to the question is that a binding agreement can only be established after the offeree's letter has been received by the offeror. Simply posting the acceptance is not enough to establish a binding agreement - the offeror needs to receive the offeree's acceptance before the agreement is legally valid.