Hello Joe1234, I’m delighted to see someone with such a scientific spirit attacking this problem, but I’m disappointed by the way you chose to conduct your experiment.
As I’m sure you know (probably far better than I) web pages often have portions that cannot be copied and pasted, and THIS web page is abundantly furnished with elements that resist highlighting (and therefore cannot be copied). Furthermore, it doesn’t contain any photos, my principal concern. So, really, there cannot be a more unsuitable guinea pig for your experiment.
Let me note for the record that although for the past month I’ve had a new computer with Windows 8, for the prior six years I was using Windows XP like you, and everything I say NOW about reproducing web pages in Yahoo Mail is equally true of my experience with Windows XP in Yahoo Mail. And I am using, and have always used, Firefox, which works much better in this regard than other browsers, in my experience.
So, let’s conduct some new experiments with web pages that are more relevant. (Since you evidently have copyright concerns, you needn’t actually email any photos that you copy, or you can email them to yourself if you want to assure yourself, without violating the law, that images are preserved during the emailing process.)
So I just did what I’ve done for many years without the slightest problem. I went to a series of randomly chosen webpages with text and photos (and sometimes non-photographic images), carefully highlighted a portion of the page (making sure the photos/images were indeed “taking” the highlighting), and then pasted it all in Yahoo Mail using Firefox. 100% of the copied photos/images were precisely reproduced in Yahoo Mail (although sometimes a little smaller in size), and were preserved intact when emailed to myself. I then repeated the exact process using LibreOffice Writer (version 3.6.32) and precisely 0 % of the photos/images were reproduced there.
So, contrary to your findings: Yahoo Mail, a complete success, LibreOffice Writer, a complete failure.
Joe1234, I eagerly await your results when you attempt to replicate my experiment.