The post office has promised to resume first class mail delivery to the area on Friday.

邮局已承诺在星期五恢复该地区第一类邮件的递送。

《柯林斯英汉双解大词典》

The cost of third-class mail has gone up by 50 per cent.

第三类邮件的邮资上涨了50%。

《柯林斯英汉双解大词典》

A: I want to send this package by first class mail.

A：我想用第一类邮件寄这个包裹。

youdao

A recent e-mail to us from Iran described an incident in an English class.

VOA: special.2009.04.23

I will use that to post information, maybe once in a while send an e-mail to the whole class.

我会在那上面发布通知,可能隔一段时间就会给全班群发一封邮件

耶鲁公开课 - 基础物理课程节选

He took a class by mail from a Minnesota art school.

VOA: special.2009.10.25

Dr. Gattuso states that 1st class mail revenues have fallen 25% in the last 6 years.

FORBES: Going Postal: How Congress Has Failed Its Shareholders

DVDs are delivered free to subscribers by first class mail, with a postage-paid return envelope, from 58 distribution centers.

ENGADGET: Netflix notches 2 billionth delivery with a Blu-ray disc HD

That wasn't nearly enough to make up for a 3.1% decline in first-class mail, still the main revenue driver.

WSJ: Postal Service Registers $5.2 Billion Loss