Found this on one of my american sites I belong too. Hope it helps.
YOU WON'T USE YOUR STORAGE IF YOU DO THE FOLLOWING:
1. Type your message and upload your pics.
2. Hit CTRL + A (that will highlight whole thing)
3. Hit CTRL + X - don't panic everything will disappear but it is on your notepad.
4. Close your message by clicking on "x" in upper right hand corner.
5. Open again and then in message portion click CTRL + V. (Make sure you click in message portion so notepad knows where) Then voila - your entire message with graphics is there and you havent used any storage. It takes a few seconds but it is so worth it. You don't have to constantly delete attachments or pictures..