airmails

airmail 与 regular mail（普通邮件）的区别在于运输方式，airmail 通过航空运输，通常速度更快，适用于国际或远距离邮件。

airmails (noun) - letters or packages sent by air, typically faster than regular mail.

• The company uses airmails to ensure that documents reach their destination within 24 hours. (使用航空邮件确保文件在24小时内到达目的地。)
  She sent the package by airmail to expedite its delivery. (她通过航空邮件寄送包裹以加快递送速度。)

Airmails are a method of sending mail that involves transporting letters, packages, or other items by airplane. This method is typically faster than sending mail via land or sea, making it a preferred choice for urgent or international deliveries. The term "airmail" can also refer to the service or system that handles such mail. In some contexts, "airmail" can be used as a singular noun, but it is more commonly used in the plural form, "airmails," to refer to multiple items sent by air.