thư gửi bằng đường bộ
The phrase "surface mail" originated in the mid-19th century, when steamships and trains were revolutionizing transportation. Prior to this, mail was carried primarily by sailing ships and horse-drawn carriages, which were slower and more unpredictable. With the advent of steam power, mail could now be transported more quickly and efficiently across the country. To distinguish this faster and more reliable method of mail transport from the older, slower methods, postal services began to refer to it as "surface mail". This term emphasized that the mail was being carried by land or sea, as opposed to being carried by air, which was not yet a viable option. Today, the term "surface mail" is still used to refer to mail that is transported by land or sea, as opposed to air mail or priority mail.
Mail transported by land or sea, as opposed to by air; a postal service for transporting mail in this way; frequently opposed to airmail.
Thư được vận chuyển bằng đường bộ hoặc đường biển, trái ngược với đường hàng không; một dịch vụ bưu chính để vận chuyển thư theo cách này; thường xuyên phản đối đường hàng không.
