Should PMs stay in Outbox when you've sent them?

[Basemetal]

Curious,
I sent a PM last night (or at least I think I did), but it doesn't show up in my sent box but stays in the Outbox. The text on the PM now says 'sent by'... with a timestamp.

Why wouldn't it have moved to the sent box?

Cheers,
Danny

[Paul Webster]

It stays in the outbox until the recipient has read it - once they have, it moves to sent.

[Basemetal]

Nice system
First time I've come across it - I thought I had a problem at my end.
Thanks for explaining