Why regex is not email validation

Regex can check whether an address looks plausible. It cannot tell you whether the domain accepts mail, whether the mailbox is disposable, or whether the server rejects the recipient.

{
  "email": "user@example.com",
  "is_valid": true,
  "status": "valid",
  "sub_status": null,
  "score": 85,
  "confidence": "high",
  "checks": { "mx_found": true, "is_disposable": false, "is_role_based": false },
  "response_time_ms": 41
}

mxping treats validation as a network check. That keeps signup forms simple while giving product and abuse teams better signal.