As soon as you "send" your PM the recipient is notified that there is a PM waiting for them, these PMs then sit in your Outbox until who they where sent to have read it - then when the recipient has read it the PM automatically gets moved to your Sent box.
This mechanism is your confirmation that lets you know that your PMs have been actually been opened/read by the recipient.
If there is still a PM in your Outbox it means that the forum member you sent it to has not read it yet.
![Very Happy :D](./images/smilies/icon_biggrin.gif)
Regards
Wayne(Coke)
Admin