I PM'd Gary But...

He hasn't responded yet (only been two days) and the PM is showing in my "outbox" instead of in the sent items. My question is, if it is in the outbox, does that mean it has or has not been sent? I would expect it to be in my sent items if it went through, so I wanted to double check. Obviously, I don't send a lot of PMs, so I am new to the process.