by post

我通过邮寄收到了生日贺卡。

I received my birthday card ___by ___post.

你可以把申请表邮寄给我们。

You can send the application form ___by ___post.

我妈妈喜欢通过邮寄订购书籍。

My mum likes to order books ___by ___post.

这封信是昨天邮寄到的。

This letter arrived ___by ___post yesterday.