add validators module with a first email validator

authentic2/locale/fr/LC_MESSAGES/django.po

@@ -7,8 +7,8 @@ msgid ""
 msgstr ""
 "Project-Id-Version: Authentic\n"
 "Report-Msgid-Bugs-To: \n"
-"POT-Creation-Date: 2014-04-09 17:07+0200\n"
-"PO-Revision-Date: 2014-04-09 17:08+0200\n"
+"POT-Creation-Date: 2014-04-23 17:18+0200\n"
+"PO-Revision-Date: 2014-04-23 17:19+0200\n"
 "Last-Translator: Mikaël Ates <mates@entrouvert.com>\n"
 "Language-Team: None\n"
 "Language: fr\n"
@@ -420,6 +420,22 @@ msgstr "valeur d'un attribut"
 msgid "attribute values"
 msgstr "valeurs des attributs"
 
+#: validators.py:19 validators.py:48
+msgid "Enter a valid email address."
+msgstr "Entrez une adresse de courriel valide."
+
+#: validators.py:34
+msgid "Invalid email address."
+msgstr "Adresse de courriel invalide."
+
+#: validators.py:41
+msgid "Nonexistent domain."
+msgstr "Domaine inexistant."
+
+#: validators.py:43
+msgid "Nonexistent email address."
+msgstr "Adresse de courriel inexistante."
+
 #: views.py:174
 msgid ""
 "Your request for changing your email is received. An email of validation was "

authentic2/validators.py

@@ -0,0 +1,50 @@
+from __future__ import unicode_literals
+
+import smtplib
+
+from django.utils.translation import ugettext_lazy as _
+from django.core.validators import EmailValidator, email_re
+from django.core.exceptions import ValidationError
+
+import dns.resolver
+
+# copied from http://www.djangotips.com/real-email-validation
+class EmailValidator(EmailValidator):
+
+    def __call__(self, value):
+        super(EmailValidator, self).__call__(value)
+        try:
+            hostname = value.split('@')[-1]
+        except KeyError:
+            raise ValidationError(_('Enter a valid email address.'))
+
+        try:
+            for server in [ str(r.exchange).rstrip('.') \
+                            for r \
+                            in dns.resolver.query(hostname, 'MX') ]:
+                try:
+                    smtp = smtplib.SMTP()
+                    smtp.connect(server)
+                    status = smtp.helo()
+                    if status[0] != 250:
+                        continue
+                    smtp.mail('')
+                    status = smtp.rcpt(value)
+                    if status[0] != 250:
+                        raise ValidationError(_('Invalid email address.'))
+                    break
+                except smtplib.SMTPServerDisconnected:
+                    break
+                except smtplib.SMTPConnectError:
+                    continue
+        except dns.resolver.NXDOMAIN:
+            raise ValidationError(_('Nonexistent domain.'))
+        except dns.resolver.NoAnswer:
+            raise ValidationError(_('Nonexistent email address.'))
+
+
+validate_email = EmailValidator(
+    email_re,
+    _('Enter a valid email address.'),
+    'invalid'
+)

requirements.txt

@@ -7,3 +7,4 @@ django-debug-toolbar<1.0.0
 --allow-external django-admin-tools
 --allow-unverified django-admin-tools
 django-admin-tools>=0.5.1
+dnspython

setup.py

@@ -119,7 +119,8 @@ setup(name="authentic2",
         'django-model-utils',
         'django-registration>=1',
         'django-admin-tools>=0.5.1',
-        'django-debug-toolbar<1.0.0'],
+        'django-debug-toolbar<1.0.0',
+        'dnspython',],
       zip_safe=False,
       classifiers=[
           "Development Status :: 5 - Production/Stable",