Hi, Hope this works on your technology like it works on mine:
-After writing your message, scroll down and click on Manage Attachments
-Then click Choose File. Your pictures, wherever they are, should show up (mine are on the desktop home page)
-Choose one, then click the site's Select. Then click their Upload.
-Close their window and click Submit Reply
-***You won't see it attached but it's there and will show up after you've finished the post***
-All this must be repeated for each photo even if you want to attach several to one message
I had to write all this down on paper in order to follow it, then was confounded when the pic was nowhere to be seen. I gave up and just sent the post. Surprised when it was there!
The "exceeds data" thing could be either that you have too much stored and need to trim some pics/info out to match up with this site, or maybe the photo was too big and if you have a choice of sending small, med, or large, medium is usually a size that will get through while being big enough to see here.
Good luck, if this doesn't work exactly with your system, hopefully it will at least inspire a technique that does get it accomplished.