Mostly for the fun of it, I have been using the Axigen mail server on my personal desktop machine. Indeed, you don’t really need a mail server on a personal machine, but I was curious about it.
After more than ten years, they changed their policy about free license, and so I have to discontinue to use it.
As far as I can say, Axigen is pretty good, it worked seamlessly on my machine, and its GUI is very friendly, powerful I would say. A couple of time I needed help, then forum support was prompt and effective.
So, thanks so much to Axigen and its team. Good luck to you!