[ryanjamurphy]

Apple Mail's not quite as customizable, indeed. Maybe close though.

I made a table comparing different email services on the MacPowerUsers forum a while back. It's in need of updating but might be handy: https://talk.macpowerusers.com/t/icloud-mail-fastmail-gmail-...

[outcoldman]

Thank you, this is useful. And actually brings the most important concern: the support. If something will go wrong, you can talk to real people behind FastMail. In case of Apple - not sure what is going to happen.