curl --request POST \
  --url https://connect.pingback.com/v2/email-verification/{email} \
  --header 'Content-Type: application/json' \
  --header 'x-api-key: <api-key>' \
  --data '
{
  "port": 25,
  "fqdn": "mail.example.org",
  "sender": "name@example.org",
  "timeout": 10000,
  "attempts": 3
}
'

{
  "message": "Email verified",
  "data": {
    "email": "example@email.com",
    "valid": true,
    "message": "Valid email (ignored SMTP verification"
  }
}