Not OP but I recently switched to Fastmail myself. It's web interface is a bit bland but you can use IMAP/SMTP and your device's built in client if that's an issue

Liking it so far, really liking being able to attach my domains natively to my inbox

Not OP, but I switched to my domain provider's email service. I use IMAP on my phone and POP3 on my computer, so when I'm away I can sneak-peek via the phone, but when I'm at my computer I pop the messages and classify locally, which removes them from the server. The cheapest mail service out there is about $5/mo, but this way all I pay is the annual renewal about $10.