https://valetudo.cloud/

Best option right now if you want a fully functional robot vacuum without any privacy concerns.

Cloudflare has a catch-all option that you can enable, but they only allow you to receive emails not send them. https://developers.cloudflare.com/email-routing/setup/email-routing-addresses/

Oh ok you should probably clarify that in the OP since everyone is giving you recommendations of self hosted software. It’s usually assumed that’s what someone’s after when they are asking for a FOSS service.

Why is Nextcloud not what you’re looking for? Sounds perfect for what you’re after.

I wouldn’t join a private tracker that requires me to expose my real IP. It doesn’t sound serious at all.