Contracts exist to provide a formal, written agreement with regards to an exchange of promises made. Because of the complex nature of contracts and the sensitive matter it addresses, many laws have been created to address most of the problems or issues that arise from entering into a contract. One such legal doctrine created regarding contracts is the recognition of mail as a reasonable form of acceptance, and that the person accepts whatever is mailed on the day that it is dropped in the mailbox and postmarked. This is referred to as the mailbox rule. This rule was initially established in the 1800s, and is continued to be observed and recognized as a rule of law until today.
The mailbox rule applies not only to legal documents, such as civil summons, but also includes payments with regards to insurance premiums. This means that payment of insurance premiums is essentially a form of acceptance of the contract that comes with the insurance.
The mailbox rule can also be referred to as the postal acceptance rule, the posting rule, or the postal rule. All refer to the same general principle. The extent of the application of the mailbox rule is limited to acceptances. Thus, a rejection letter is not considered to be valid on the date it is postmarked. It is important to take note of the mailbox rule whenever entering into contracts. It is usually placed in a separate provision entitled as it is, and provides for the exact details as to when an acceptance is considered an acceptance.