Well, with the exposed in the first post and later link I have almost finished the task. Anyone with these two things and a little patience could do this simple plugin.
Although everything seems to be correct (in fact no error or anything similar is shown) the email does not arrive, but that would be for another post.
Thank you very much to all!
Amazing help!
From what I have seen I was on the right track (I think). In addition, this solution is done through a plugin that was the next task that was pending. I will do!
A million thanks!
Could it be a solution to add images of adequate size (in this case the same as the rest of the gallery) transparent (or white in this case)?
