What does outbox mean?
An outbox is a place where outgoing material is collected before it is sent. In email and other messaging systems, it usually means a folder or queue containing messages that have been composed but not yet transmitted. An item may remain there while the system waits for a connection, encounters an error, or is configured to send at a particular time. In offices, the word can also refer more traditionally to a tray or box for outgoing post, although “out tray” is often more natural in British English. The word is especially useful because it distinguishes material that is ready to go from material that has actually been transmitted. Its opposite in electronic communication is the inbox, although the comparison is imperfect: an inbox is where incoming messages arrive, whereas an outbox holds outbound messages awaiting delivery. Technical writing also uses “outbox” for a database pattern in which messages to be sent are written reliably before they are dispatched. Overall, the term evokes both the physical act of dispatch and the waiting state between preparing a message and sending it.
nounA designated area in an email or messaging system where outgoing messages are held before transmission; more broadly, a queue or store of items awaiting transmission. In an office, it can also refer to a tray or container for outgoing mail.
- A folder, queue, or other designated area in which outgoing electronic messages or data are stored before being transmitted.
- A tray, box, or receptacle used to collect outgoing mail or papers.
"The message remains in the outbox until the system reconnects to the mail server."
"A temporary connection failure left the report sitting in her outbox."
"The receptionist emptied the office outbox before leaving for the day."
The standard plural adds -es. In compound constructions, “outbox” is usually used in the singular.
"The two outboxes were empty at the end of the day."
An outbox is the digital cousin of the office out tray: both hold messages on their way out.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Where does outbox come from?
Outbox is an English compound formed from the preposition or adverb “out” and the noun “box.” The element “box” comes through Medieval Latin buxis from Greek pyxis, meaning a box or container, while “out” is native to English and Germanic. The familiar electronic-communication sense developed during the widespread adoption of email and other networked messaging systems.
Related word forms
How outbox is actually used
The electronic sense is now dominant and is common in general computing, although it can sound technical outside discussions of email or software. Capitalized “Outbox” often appears as the name of a folder or queue in an application interface. The physical sense is traditional and formal; British speakers may prefer “out tray.”
Easily confused with outbox
An outbox holds outgoing messages awaiting transmission, while an inbox holds incoming messages that have arrived.