well, the thing is that you couldn't make it simpler. Easy as pie, just follow the steps.- after you get in, go to "tous les messages", there you can read, upload a file, answer messages, write a message...simple. It's the same rule as for all the stuff that has something to do with Internet or computers; it's a question of MANIPULATION !

PS: the small icons in "nouveau message" on your top right allow you to insert an image, a video...

thanks.