I use AWS WorkMail and I'm moderately happy with it. It's pretty barebones, but works and hasn't given me any problems. I went with it because I use Route53 for

I use AWS WorkMail and I'm moderately happy with it. It's pretty barebones, but works and hasn't given me any problems. I went with it because I use Route53 for my domains, and host most of my stuff on AWS anyway, so it was one less account/service to manage. The web interface is really basic, but I mostly access it through emacs/gnus or the android email client. My only complaint is that some of the documentation is wrong. It tells you to use an exchange setup for android, but that breaks. The plain IMAP setup works fine though. I can't really speak to privacy aspects, but I'm assuming that since I'm actually paying for the service, it's a little better than if I were using a free service like gmail.