It's also expensive compared to rolling my own. Using the standard plan, I'd be paying 200$/y for just a single address for each of my family members. Personally, I want at least 2 myself. Compare that to the ~120$/y I pay for my main VPS which has plenty of spare resources to handle not only my family's email, but also for some clients AND, since I make the rules, I also don't need services like Sendgrid for sending email from my websites. All well worth the 5-10 afternoons a year spent maintaining it.