We sent the letter by air mail.

我们通过空邮寄信。

youdao

Send it by air mail if possible.

如有可能请用航空邮件寄。

youdao

How much is it to send this parcel by air mail?

欲通过航寄发送这小包需要多少钱？

youdao

This year, visitors are delighted to be returning to Bethlehem, where they can send franked letters by first class or by air mail.

BBC: Bethlehem post attracts festive flock

Correspondents did as they were bidden, filing their copy by air-mail letter or, in later years, by telex.

ECONOMIST: Nancy Balfour

"We are mapping out a return-to-service plan, and we look forward to getting our 787s back in the air, " she said by e-mail.

NPR: FAA Approves Resumption Of Boeing 787 Flights