It is Photobucket.com. When you go there you need to join. pretty much the same as joining here.
When you have sent your photos there, again good easy on screen instructions there to transfer them here is not hard. When your photo appears in you album, underneath are three lines, the bottom one is the one you need. If you click on it, the line turns blue. You may then copy that line (Ctrl+C or EDit Copy). Then go to this site, start your message and when you want the photo to appear press Ctrl+V or Edit Paste. Then Preview to see if it has worked. Hope this is enough for you. If not please ask again and I will give even more details.