DNS record check now passes if email address has no top-level domain (#355)

src/Validation/DNSCheckValidation.php

@@ -123,9 +123,20 @@ class DNSCheckValidation implements EmailValidation
     {
         $variant = INTL_IDNA_VARIANT_UTS46;
 
-        $host = rtrim(idn_to_ascii($host, IDNA_DEFAULT, $variant), '.') . '.';
+        $host = rtrim(idn_to_ascii($host, IDNA_DEFAULT, $variant), '.');
 
-        return $this->validateDnsRecords($host);
+        $hostParts = explode('.', $host);
+        $host = array_pop($hostParts);
+
+        while (count($hostParts) > 0) {
+            $host = array_pop($hostParts) . '.' . $host;
+
+            if ($this->validateDnsRecords($host)) {
+                return true;
+            }
+        }
+
+        return false;
     }
 
 

tests/EmailValidator/Validation/DNSCheckValidationTest.php

@@ -21,6 +21,7 @@ class DNSCheckValidationTest extends TestCase
         return [
             // dot-atom
             ['Abc@ietf.org'],
+            ['Abc@fake.ietf.org'],
             ['ABC@ietf.org'],
             ['Abc.123@ietf.org'],
             ['user+mailbox/department=shipping@ietf.org'],
@@ -149,4 +150,4 @@ class DNSCheckValidationTest extends TestCase
         $validation->isValid('example@invalid.example.com', new EmailLexer());
         $this->assertEquals($expectedError, $validation->getError());
     }
-}
+}