They also support native Apple iOS push notifications (not just for new mail, but also edits/deletes IIRC), so their integration with Apple's native iOS mail ap

They also support native Apple iOS push notifications (not just for new mail, but also edits/deletes IIRC), so their integration with Apple's native iOS mail app is outstanding. Been using FastMail that way for years and it's been working flawlessly. About the only time I use the Fastmail app is when I want to reply to an email sent to a catch-all address and reply from that address (haven't found a way to do that from the native Apple mail app).