Andrew S.
Easy setup, modern UI, support from humans
I created a trial account on MangoMail. Adding my custom domains was the simplest I have seen. The setup process provided me the list of DNS settings required, with tips explaining each setting, clickable buttons to copy each setting value, and the buttons change to ticks after being clicked so you can see which values you have already copied. The whole process of signing up, adding custom domain and configuring email client took less than 10 minutes. I was immediately able to send and receive test emails to verify the new account was working. After spending some time exploring the service, I realised they didn't have a feature I wanted, so I decided end my trial and look for an alternate service. When I cancelled the trial, I was asked to provide feedback which I did. 3 minutes later I received an email thanking me for my feedback and advising that they are working on that feature and plan on releasing it in the near future. After some emails back and forth, I was so impressed with their support that I reactivated my account, and now have a paid subscription!