Catch-all mailbox hint (no SMTP probing): estimates whether a domain accepts mail to any address, from provider defaults (Google Workspace/Microsoft 365 usually reject unknown users; many small hosts and Cloudflare Email Routing accept all), wildcard DNS and MX shape. Helps interpret 'deliverable: likely' results. $0.01 per domain.
| Network | Scheme | Amount | Pay To |
|---|---|---|---|
| Base | exact | $0.01 USDC | 0x91D5...0abd |
| Base Sepolia | exact | $0.01 USDC | 0x91D5...0abd |