// Usage $result = validateEmail("user+tag@example.com"); if ($result['valid']) echo "Valid: " . $result['email'];

?>

// Optional DNS check if ($checkDNS) $domain = substr(strrchr($email, "@"), 1); if (!checkdnsrr($domain, 'MX') && !checkdnsrr($domain, 'A')) return ['valid' => false, 'message' => 'Domain has no mail server'];

Complex email regex is notoriously error-prone. Stick with filter_var() for standard validation. 5. Advanced: Check if Email Actually Exists (SMTP Verification) For real-time existence checks (without sending email), you can attempt an SMTP handshake:

function validateEmail($email) // Remove illegal characters $sanitized = filter_var($email, FILTER_SANITIZE_EMAIL); // Validate if (filter_var($sanitized, FILTER_VALIDATE_EMAIL)) return ["valid" => true, "email" => $sanitized];