...and it goes in your Outbox, what exactly does it mean when this symbol: http://manchester.flirtbox.co.uk/images/newmessage.gif
is next to it?

'cause I'm actually not sure if the message has even been sent

Messages are not "sent" as such - they are inserted into the database. So when you see it, it is there and it can be read by yourself and the one you have sent it to!

but see the thing is I keep sending messages, which never recieve replies. And it's just all recent ones with the little clippy thingy symbol next to them.

I have sent messages before which I have gotten replies from which is why I'm wondering if there's some sort of problem here...

The little clippy thing as you put it means that the message you have sent has not been read by the person who you have sent it too, it stays like that until read & then the clippy thing disappears, hope that this helps

Errrmmm, yeah, what she said....

Got my Teacher head on putting my tutoring skills to use, erm! cough!!