Yeah, no, jpegs should never be 20MB.
I wasn't at all surprised to see you say "him" in this post. It must be a penis-related thing, it so often seems to be men who demand outrageously big files. He is an idiot, of course. The problem is that people like this think they know something about digital imaging, but of course they don't.
On average, what are the pixel dimensions of the files you sent him? And what quality level did you save them at?