1. at the post office：在邮局

e.g. Yesterday he met some old friend of his father's at the post office.

昨天在邮局他遇到了他父亲的一位老朋友。

e.g. Is mail kept at the post office until someone goes there to get it?

是不是邮件保存在邮局等收件人来取呢?

e.g. I have a new hat that I bought for twenty-five cents at the post office.

我花了25美分在邮局买了一顶新帽子。

e.g. I asked the driver to put me off at the post office.

我请司机让我在邮局门口下车。

2. after all：毕竟，终究

e.g. He reversed the judgment and set the prisoner free after all.

他撤销了原判，终于释放了囚犯。

e.g. After all these years, we've at last paid off all our debts.

经过这么多年，我们总算把债还清了。

e.g. He rejoiced that all the work was after all finished in time.

他很高兴,全部工作到底还是按时完成了。

e.g. After all, nearly everyone spends money on some hobby or other.

话说回来，几乎每个人都要花点钱在某种嗜好上面的。