They were supposed to mail back the form last month.

VOA: special.2010.05.07

How many of you did not bring the passages that I sent to you by e-mail last night?

你们中有多少人没有带讲义,我昨晚用邮件发给你们的？

耶鲁公开课 - 文学理论导论课程节选

The last regular mail delivery was on September 19th, and thereafter they used balloons.

最后一封常规邮件于九月十九日发出,在那之后他们只能用热气球传送消息

耶鲁公开课 - 1871年后的法国课程节选