Sent v. Outbox

[Irlandos]

Can someone explain to me the difference between the Sent and Outbox folders?
I send messages and sometimes they end up in one folder, sometimes in the other.
Thanks!

[VPaulus]

The Sent folder it means your message's recipient received it.
The Outbox folder is the one where the message stays until the recipient didn't received it yet.

[PoorOldSpike]

Yes, most other internet forums use the same method too. Outbox means the recipient hasn't read it yet..