outbox
noun [ C ] uk/ˈaʊt.bɒks/ us/ˈaʊt.bɑːks/
（电子邮件的）发件箱
a place on a computer where copies of email messages that you are going to send are kept
US (UK out tray)（办公桌上存放已处理或待发文件的）发文篮，待发信件盘
a flat, open container on a desk for letters and other documents that have already been dealt with and are waiting to be sent to someone else or put away
The letter is in your outbox. 那封信在你的发文篮里。