Thanks for the very helpful feedback.

Last time I used Fastmail, I had to manually setup the aliases in advance, before they could receive mail. It also isn't possible to send from aliases on Fastmail. I find Fastmail's UI/UX to be too cumbersome for what I want to do with my email.

Once I've added a few more key features and polished the UI a bit, I am planning on revamping the landing page to make things clearer.

Thanks again for the feedback. It's incredibly useful.