- An electronic folder for outgoing e-mails or text messages.
- A container for outgoing documents, located in or near one's office or work area.
- A box holding all the mail to be sent out.
- (computing) An electronic folder serving the same purpose, for electronic mail.
(third-person singular simple present outboxes, present participle outboxing, simple past and past participle outboxed)
- (boxing) To box better than.