But what's the alternative? Does SMTP even work without a domain? I dipped my toes in this far enough to connect a custom domain to a mailbox hosted by bluehost so I don't know too much but I always seek to separate from Google et al wherever possible. I thought the buck stops at DNS and domain registration though, short of like, that gnu internet project I vaguely remember, what's the alternative?
It is, but don't expecting people understand what komali@13.55.66.77 is a perfectly valid address, nor the anti-spam systems or designers of web/mail apps and services.
You can theoretically send email to an IP address directly, like someone@[127.0.0.1], but I imagine a lot of the programs and websites you'd want to use don't know that. And you're still left with the problem of needing to get that IP address from someone who can arbitrarily take it away from you.
