Nice. Curious if they will also let Mythos and related LLM's also take a pass at it.

Same. I've been a fastmail user for years and JMAP is a must-have for me now. But infra is so much easier to manage than it used to be, and I see projects like this and I'm thinking it could just be my own affordable box in the cloud now (that I could use for other servers as well).

Whenever your email doesn't get delivered, you just resend it from your Gmail account. Receiving always works.

I've been self-hosting my email for years. Something that wasn't obvious to me in the beginning is that you can separate sending and receiving: host the receiving yourself and use a service for sending (e.g. Mailchimp, Sendgrid etc.). That can address many concerns.

I did that in the beginning but later set up my own relay hosted at Hetzner. I could do it on my receiving server (a PC in my house) but I don't have a static IP and IP reputation is a big deal in email deliverability.

I do very occasionally get sent to spam but it's fairly rare and I'm not sure my free Gmail account was any better.

Even a custom domain can be pain. I have an xyz domain and my mails usually land in the spam folder when I send from it. If you don't have enough volume you might have trouble as well.