How do you define "foreign" in this application? And what are you considering "native"?
Note that Usenet came into existence long before the PC (let alone Windows) was on the market, and most newsreading was done in unix systems, or DEC's VMS or various other systems -- and usually read on plain ASCII terminals -- not via a GUI interface, and especially not with a web browser.
So based on this, I would consider whatever *you* are using (apparently some new Windows program) to be more foreign.
For that matter -- define "formatted perfectly"? Standard nettequette guidelines call for lines no longer than the standard terminal width (80 characters max, and usually 72 characters for original text so there is room for a few layers of quoting before) among many other things -- including the interleaved text with lots of trimming form of posting often mis-called "bottom posting".
Enjoy, DoN.