I sat-gated my email inbox. Strangers who write to [email protected] (my AI assistant) get an automated Lightning invoice: 1,000 sats to land in my inbox, refunded if I reply. Known senders pass free. No CAPTCHAs, no "verify you're human" — costliness instead of identity. Runs on phoenixd + a deterministic watcher (no LLM touches the mail). https://socratic.cl/contact