Some servers demand MAIL FROM: <email> before asking

validate_email.py

@@ -95,6 +95,7 @@ class ServerError(Exception):
 MX_DNS_CACHE = {}
 MX_CHECK_CACHE = {}
 
+logger = logging.getLogger('validate_email')
 
 def get_mx_ip(hostname):
     if hostname not in MX_DNS_CACHE:
@@ -109,7 +110,25 @@ def get_mx_ip(hostname):
     return MX_DNS_CACHE[hostname]
 
 
-def validate_email(email, check_mx=False, verify=False, debug=False, smtp_timeout=10):
+def check_command(result_tuple, server_name='server', ok_codes=None, debug=False):
+    status, mes = result_tuple
+    if not ok_codes:
+        ok_codes = [250]
+    if status not in ok_codes:
+        if debug:
+            logger.debug(u'%s answer: %s - %s', server_name, status, mes)
+        return False
+    return True
+
+
+def check_command_for_server(server_name):
+    def wrapper(*args, **kwargs):
+        kwargs['server_name'] = server_name
+        return check_command(*args, **kwargs)
+    return wrapper
+
+
+def validate_email(email, check_mx=False, verify=False, debug=False, mail_from='', smtp_timeout=10):
     """Indicate whether the given string is a valid email address
     according to the 'addr-spec' portion of RFC 2822 (see section
     3.4.1).  Parts of the spec that are marked obsolete are *not*
@@ -118,10 +137,7 @@ def validate_email(email, check_mx=False, verify=False, debug=False, smtp_timeou
     general this should correctly identify any email address likely
     to be in use as of 2011."""
     if debug:
-        logger = logging.getLogger('validate_email')
         logger.setLevel(logging.DEBUG)
-    else:
-        logger = None
 
     try:
         assert re.match(VALID_ADDRESS_REGEXP, email) is not None
@@ -136,38 +152,37 @@ def validate_email(email, check_mx=False, verify=False, debug=False, smtp_timeou
                 return False
             for mx in mx_hosts:
                 try:
-                    if not verify and mx[1] in MX_CHECK_CACHE:
-                        return MX_CHECK_CACHE[mx[1]]
+                    server_name = mx[1]
+                    check = check_command_for_server(server_name)
+                    if not verify and server_name in MX_CHECK_CACHE:
+                        return MX_CHECK_CACHE[server_name]
                     smtp = smtplib.SMTP(timeout=smtp_timeout)
-                    smtp.connect(mx[1])
-                    MX_CHECK_CACHE[mx[1]] = True
+                    smtp.connect(server_name)
+                    MX_CHECK_CACHE[server_name] = True
                     if not verify:
-                        try:
-                            smtp.quit()
-                        except smtplib.SMTPServerDisconnected:
-                            pass
                         return True
-                    status, _ = smtp.helo()
-                    if status != 250:
-                        smtp.quit()
-                        if debug:
-                            logger.debug(u'%s answer: %s - %s', mx[1], status, _)
+
+                    if not check(smtp.helo()):
                         continue
-                    smtp.mail('')
-                    status, _ = smtp.rcpt(email)
-                    if status == 250:
-                        smtp.quit()
+
+                    if not check(smtp.mail(mail_from)):
+                        continue
+
+                    if check(smtp.rcpt(email)):
                         return True
-                    if debug:
-                        logger.debug(u'%s answer: %s - %s', mx[1], status, _)
-                    smtp.quit()
                 except smtplib.SMTPServerDisconnected:  # Server not permits verify user
                     if debug:
                         logger.debug(u'%s disconected.', mx[1])
                 except smtplib.SMTPConnectError:
                     if debug:
                         logger.debug(u'Unable to connect to %s.', mx[1])
-            return None
+                finally:
+                    try:
+                        smtp.quit()
+                    except smtplib.SMTPServerDisconnected:
+                        pass
+
+            return False
     except AssertionError:
         return False
     except (ServerError, socket.error) as e:
@@ -193,9 +208,11 @@ def validate_email(email, check_mx=False, verify=False, debug=False, smtp_timeou
         else:
             validate = False
 
+        sender_address = raw_input('Use sender address? [<email>] ').strip()
+
         logging.basicConfig()
 
-        result = validate_email(email, mx, validate, debug=True, smtp_timeout=1)
+        result = validate_email(email, mx, validate, debug=True, mail_from=sender_address, smtp_timeout=1)
         if result:
             print("Valid!")
         elif result is None: