There is mail in your mailbox six days a week so take time out to thank the mail person who is responsible for getting it there! Thank A Mail Carrier Day is February 4th and a reminder of how important mail carriers are to our everyday lives. Their motto “Through rain or snow, or sleet or hail, we’ll carry the mail. We will not fail.” Postage stamps were invented in 1847 and in 1963, the Zip Code began! Mailing a card in the mailbox.