The problem with trying to install older Microsoft programs onto Window 10 machines is that, even if there are posts on the web stating that it worked for some people, it might not work for everyone. (There might be hardware issues or, for example, a Windows 10 update might prevent a successful installation working even though it would have been possible when Windows 10 first came out).
If you can find the original setup file on your old machine then, after copying it across on a USB memory stick (for example) you might be able to get it to run on your Windows 10 machine but, if the Softpedia download didn't work, I doubt that it will.
Using Thunderbird is a better option:
https://www.thunderbird.net/en-GB/