In case folks were not aware, Fastmail is a Calendar, Contacts, Drive, and Keep replacement too, all built on open standards so you can use your favorite tools to interact with them
Since you're a paying customer, there's no front page posts ever saying "I got locked out of my account and there's no one to call" as with some other free mail provider I can think of
A really nice feature of Fastmail is "virtual domains" where you can receive emails on multiple domains in the one inbox. It's a 5 min job to setup email capability (including wildcard addressing) on any new domain you get.
They've made it very simple and easy to configure.
Another fun trick is their partnership with 1Password to make "masked emails"; all the fun of mailinator but with much less hassle: https://support.1password.com/fastmail/
Since you're a paying customer, there's no front page posts ever saying "I got locked out of my account and there's no one to call" as with some other free mail provider I can think of