My guess is that it stays in your outbox until the other person(s) read it. My guess at times it may hang if the other persons inbox is full and they may not receive any new messages until they clean up their inbox. But remember I am just guessing.
I don't know, Kurt, you may be right. I had logged all the way off the internet and then back in to my User Control Panel several times before I posted my question only to find my PM always stuck in my Outbox. Then after reading your response, I logged in again to find it gone from the Outbox and in my Sent folder.
In addition to mastery of the occult programing arts, do you have trans-Atlantic superpowers you haven't told us about yet?
Well, I have to go now - time to ask INNERBREED
about his robotics room again.