If you get this message when you first open the Send Email window, it is more than likely that your browser is having some sort of security concern. It is not passing your login information to the pop-up window so it thinks you are not logged in.
The easiest way to rectify this problem is to close down all your browser windows and then start again.
If the problem persists you should check that AdultWork.com is not being blocked in any way by any Internet Security or firewall type products that you may have installed.