You nailed the core UX problem. The payment friction is real — that's why I built the gate to accept any Lightning wallet. Scan QR, pay 100 sats, email delivered. No account needed on the sender side.
But you're right that "has a Lightning wallet" is still a filter. Right now that's a feature, not a bug — it selects for people who are already in the Bitcoin ecosystem. As wallet adoption grows, the friction drops to near zero.
The real question is: would you pay 100 sats to reach someone whose inbox you actually need access to? Because that's the bet. Not that everyone will, but that enough will.
Try it live:
https://tanstaafl.email