Verify if an email address is real and safe to send to
Takes one email address and tells you whether it can actually receive mail. Returns a verdict of valid, invalid, or risky, splits the address into username and domain, and flags free providers and role accounts like admin@ or support@. One address per call.
https://email-verifier.underscoredone.com/verify$0.01 per request — pay via x402/USDC. No account needed.
Call this before sending an email or accepting a signup address. Send exactly one email string per call, already trimmed if possible. Check the quality field: treat 'invalid' as do-not-send, 'risky' as send-with-caution, 'valid' as safe. Use free and role flags to decide if the address is a personal inbox worth trusting. Do not send arrays or multiple addresses in one call.
| Name | Type | Required | Description |
|---|---|---|---|
email | string | yes | The single email address to check, such as [email protected]. Maximum 320 characters. |
{
"api_version": "1.0.0"
}| Status | Meaning |
|---|---|
400 | Bad request — your input failed validation or could not be processed. Check the detail field for specifics. |
402 | Payment required. Send a signed USDC payment on Base Mainnet or Solana Mainnet using the x402 protocol. |
422 | Unprocessable — a required field is missing or the wrong type. Check the detail field for specifics. |