There appears to be webmail support on Frogwares' website.
If you go to
http://frogwares.com/support/and expand the list, 80 Days is there near the bottom.
I don't know if they'll answer a support request, but I can't find help for running this game on Windows 10 anywhere else.
Most of my searches either turn up a completely different game with the same title, or turn up old reviews.