The reason Fastmail's feature matters is specifically because it's not using the + trick or a catch-all domain. They're 'real' aliases, not just Regex filters o

The reason Fastmail's feature matters is specifically because it's not using the + trick or a catch-all domain. They're 'real' aliases, not just Regex filters or wildcards. If you're using the + trick, you haven't gained any privacy, because I can strip the + and get your original address. If you're using a catch-all domain, you haven't gained any privacy, because the domain remains a unique identifier for your all of your accounts. It's good for organizing, but not for privacy, because you're still publicly attaching your identity to every email you send. With fastmail, I don't need to do myaddress+walmart@fastmail.com or walmart@danshumway.com. I can just do walmart@fastmail.com. That's a really large privacy win, since it gets rid of one of the biggest and least regulated unique identifiers that services can share with each other. I don't know if other providers like Outlook are also offering 'real' aliases. I'm happy if they are, I think this should be an industry standard feature. Either way, switching to any provider does will be a pretty significant feature upgrade over Gmail, even if you're currently using a paid Gmail account with your own domain.