The top comments on that thread discuss the importance of owning your email address by way of using a custom domain, so you can move to a new providers and not worry about losing contacts or missing emails. I fully agree with that.

Back in 2014, both Outlook and Gmail had free family plans with custom domain capability, but have since removed those options. Is there a good low-cost option for custom domain email in 2019? For people who use and rely on email a lot, Fastmail is definitely the best option, but it is too expensive for my use case. I would like to set up custom domains for my family (5-10 people in total) and I would like to know what is the cost-effective best practice to do so these days.