A postmark is the official mark the post office prints on a letter or a parcel. It usually shows the place and the date — sometimes the time too — when that item went into the mail.

A postmark isPostmark（郵戳）是 the post office prints on a letter or a parcel郵局蓋在信件或包裹上的 the official mark官方印記。 It usually shows它通常會顯示 when that item went into the mail這個郵件被送進郵寄系統時的 the place and the date地點和日期—— sometimes the time too有時候也有時間。

You often see it stamped right over the stamp you stuck on, so nobody can use that stamp again. That is the everyday job of a postmark: it is proof the letter really was posted, and from where.

You often see it stamped你常常會看到它蓋 right over the stamp you stuck on在你貼上的郵票正上方， so nobody can use that stamp again這樣就沒有人能再用那張郵票。 That is the everyday job of a postmark那就是郵戳每天在做的事： it is proof它就是證明： the letter really was posted信件真的被寄出了， and from where而且知道是從哪裡寄出的。

People also use it as a verb: to postmark a letter is to put that mark on it.

People also use it as a verb人們也把它當動詞用： to postmark a letterto postmark（在信上蓋郵戳）一封信， is就是 to put that mark on it把那個印記蓋在信上。

In careful talk it stays a post-office word. In looser talk someone might say “the postmark” when they only mean “the date on the envelope,” and skip the place. It is not the pretty stamp you buy; it is the extra mark the office adds.

In careful talk在講究的用語裡， it stays它仍然是 a post-office word郵局用詞。 In looser talk在比較隨性的說法裡， someone might say "the postmark"有人可能會說「the postmark」， when they only mean "the date on the envelope,"但其實只是指「信封上的日期」， and skip the place把地點省略掉。 It is not它不是 the pretty stamp you buy你買的那張漂亮郵票； it is它是 the extra mark the office adds郵局額外蓋上去的印記。