I am hoping for eM Client for Linux, too. I replied to another thread about it not knowing about this thread…
With the views on that thread and this one, eM Client is missing a lot of license sales as there is a demand for it on Linux. I know I would need a lifetime license for 4-5 computers.
They could make a Flatpak or Snap for eM Client. I would be happy with a 64-bit .DEB of eM Client, but Flatpak or Snap would be OK as well.