Another commenter mentions ProtonMail, but somewhat unadvertised is with a paid Proton sub (I forget which tier), you also get access to SimpleLogin. It's a service which lets you create new email aliases with your domain that just send them to another email you own. (Also lets you send emails as that alias, so the other end doesn't see your real address.)

I use it with Vault/Bitwarden, which lets me generate email addresses of format `<uuid>@my.domain.com` when I create new login info for services.