- A principle in contract law that establishes an offer or acceptance as valid if it is sent via post within the time frame required for acceptance, unless the offer stipulates personal delivery is necessary. It might also apply to sending insurance premium payments when due
- Under the mailbox rule, her contract acceptance was valid as it was mailed within the stipulated timeframe.
- Despite postage delays, the mailbox rule allowed his payment to be considered on time.
- They secured their contract through the mailbox rule by ensuring their mailed acceptance arrived in the proscribed period.