An outbox is the temporary folder in an email client that holds messages after you hit send but before they are actually transmitted. Once a message is delivered to the mail server, it moves out of the outbox.
Outbox vs. Sent Folder
The outbox and the sent folder are easy to confuse. The outbox holds messages that are still on their way out — queued, waiting for a connection, or being processed. The sent folder holds copies of messages that have already left. If a message lingers in the outbox, it usually hasn't been sent yet, often because the device is offline or the server hasn't accepted it.
Why a Message Stays in the Outbox
A message can sit in the outbox when there's no internet connection, the email is too large, the server is busy, or the client is set to send manually. It is closely related to a queued email — a message accepted for sending but waiting its turn. Resolving the connection or attachment issue usually lets the outbox clear and the message move to the sent folder.
How to Clear a Stuck Outbox
When a message refuses to leave the outbox, work through the common culprits in order. Confirm the device has a stable connection, since offline mode is the most frequent cause. Check the attachment size against your provider's limit and compress or link to large files instead. Make sure the client isn't paused or set to send only on a manual sync. If one oversized or malformed message is blocking the queue, removing or re-saving it often lets the rest go through. As a last resort, restarting the client forces it to retry the send.
Outbox and Topol
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