I think it depends on your IT policies. You might have to compress it which should circumvent some checks but even then it might be larger than allowed.
Most emails flag the '.prg' file, so it used to be you could just alter it to '.doc' or as you said '.prx', but now there are also file size limitations that can halt the email from being delivered. So in that case, I would alter the extension name and email them in a zipped folder.
