Add no_smtp argument that allows us to validate only mx records without SMTP request

tests/test_mx_check.py

@@ -5,8 +5,9 @@ from unittest.mock import Mock, patch
 from dns.exception import Timeout
 
 from validate_email import mx_check as mx_module
+from validate_email.email_address import EmailAddress
 from validate_email.exceptions import DNSTimeoutError, NoValidMXError
-from validate_email.mx_check import _get_mx_records
+from validate_email.mx_check import _get_mx_records, mx_check
 
 
 class DnsNameStub(object):
@@ -62,3 +63,12 @@ class GetMxRecordsTestCase(TestCase):
         with self.assertRaises(DNSTimeoutError) as exc:
             _get_mx_records(domain='testdomain3', timeout=10)
         self.assertTupleEqual(exc.exception.args, ())
+
+    @patch.object(target=mx_module, attribute='_check_mx_records')
+    def test_no_smtp_argument(self, check_mx_records_mock):
+        'Check correct work of no_smtp argument.'
+
+        self.assertTrue(
+            mx_check(EmailAddress('test@mail.ru'), debug=False, no_smtp=True)
+        )
+        self.assertEqual(check_mx_records_mock.call_count, 0)

validate_email/mx_check.py

@@ -167,7 +167,7 @@ def mx_check(
     email_address: EmailAddress, debug: bool,
     from_address: Optional[EmailAddress] = None,
     helo_host: Optional[str] = None, smtp_timeout: int = 10,
-    dns_timeout: int = 10
+    dns_timeout: int = 10, no_smtp: bool = False
 ) -> Optional[bool]:
     """
     Return `True` if the host responds with a deliverable response code,
@@ -181,6 +181,8 @@ def mx_check(
     else:
         mx_records = _get_mx_records(
             domain=email_address.domain, timeout=dns_timeout)
+    if no_smtp:
+        return True
     return _check_mx_records(
         mx_records=mx_records, smtp_timeout=smtp_timeout, helo_host=host,
         from_address=from_address, email_address=email_address, debug=debug)

validate_email/validate_email.py

@@ -13,9 +13,10 @@ LOGGER = getLogger(name=__name__)
 
 def validate_email_or_fail(
         email_address: str, check_regex: bool = True, check_mx: bool = True,
-        from_address: Optional[str] = None, helo_host: Optional[str] = None,
-        smtp_timeout: int = 10, dns_timeout: int = 10,
-        use_blacklist: bool = True, debug: bool = False) -> Optional[bool]:
+        no_smtp: bool = False, from_address: Optional[str] = None,
+        helo_host: Optional[str] = None, smtp_timeout: int = 10,
+        dns_timeout: int = 10, use_blacklist: bool = True, debug: bool = False
+        ) -> Optional[bool]:
     """
     Return `True` if the email address validation is successful, `None` if the
     validation result is ambigious, and raise an exception if the validation
@@ -37,7 +38,7 @@ def validate_email_or_fail(
     return mx_check(
         email_address=email_address, from_address=from_address,
         helo_host=helo_host, smtp_timeout=smtp_timeout,
-        dns_timeout=dns_timeout, debug=debug)
+        dns_timeout=dns_timeout, no_smtp=no_smtp, debug=debug)
 
 
 def validate_email(