feat(accounts): Allow disabling email sending to unknown addresses

Add a setting to the accounts app which disables sending emails to
addresses which do not have an account.
For many sites this behaviour will be undesirable since it sends
potentially unsolicited email to someone who has not shared it with us.

ChangeLog.rst

@@ -22,6 +22,9 @@ Note worthy changes
 - A configurable timeout (``SOCIALACCOUNT_REQUESTS_TIMEOUT``) is now applied to
   all upstream requests.
 
+- Added a setting ``ACCOUNT_EMAIL_UNKNOWN_ACCOUNTS`` to disable sending of
+  emails to unknown accounts.
+
 
 Backwards incompatible changes
 ------------------------------

allauth/account/app_settings.py

@@ -386,6 +386,10 @@ def PASSWORD_RESET_TOKEN_GENERATOR(self):
             token_generator = EmailAwarePasswordResetTokenGenerator
         return token_generator
 
+    @property
+    def EMAIL_UNKNOWN_ACCOUNTS(self):
+        return self._setting("EMAIL_UNKNOWN_ACCOUNTS", True)
+
     @property
     def REAUTHENTICATION_TIMEOUT(self):
         return self._setting("REAUTHENTICATION_TIMEOUT", 300)

allauth/account/forms.py

@@ -588,7 +588,8 @@ def clean_email(self):
     def save(self, request, **kwargs):
         email = self.cleaned_data["email"]
         if not self.users:
-            self._send_unknown_account_mail(request, email)
+            if app_settings.EMAIL_UNKNOWN_ACCOUNTS:
+                self._send_unknown_account_mail(request, email)
         else:
             self._send_password_reset_mail(request, email, self.users, **kwargs)
         return email

allauth/account/tests/test_reset_password.py

@@ -6,12 +6,36 @@
 from django.test.utils import override_settings
 from django.urls import reverse
 
+import pytest
+
 from allauth.account import app_settings
 from allauth.account.forms import ResetPasswordForm
 from allauth.account.models import EmailAddress
 from allauth.tests import TestCase
 
 
+@pytest.mark.django_db
+def test_reset_password_unknown_account(client, settings):
+    settings.ACCOUNT_PREVENT_ENUMERATION = True
+    client.post(
+        reverse("account_reset_password"),
+        data={"email": "unknown@example.org"},
+    )
+    assert len(mail.outbox) == 1
+    assert mail.outbox[0].to == ["unknown@example.org"]
+
+
+@pytest.mark.django_db
+def test_reset_password_unknown_account_disabled(client, settings):
+    settings.ACCOUNT_PREVENT_ENUMERATION = True
+    settings.ACCOUNT_EMAIL_UNKNOWN_ACCOUNTS = False
+    client.post(
+        reverse("account_reset_password"),
+        data={"email": "unknown@example.org"},
+    )
+    assert len(mail.outbox) == 0
+
+
 @override_settings(
     ACCOUNT_PREVENT_ENUMERATION=False,
     ACCOUNT_DEFAULT_HTTP_PROTOCOL="https",

docs/account/configuration.rst

@@ -72,6 +72,10 @@ Available settings:
   Subject-line prefix to use for email messages sent. By default, the
   name of the current ``Site`` (``django.contrib.sites``) is used.
 
+``ACCOUNT_EMAIL_UNKNOWN_ACCOUNTS`` (default: ``True``)
+  Configures whether password reset attempts for email addresses which do not
+  have an account result in sending an email.
+
 ``ACCOUNT_DEFAULT_HTTP_PROTOCOL`` (default: ``"http"``)
   The default protocol used for when generating URLs, e.g. for the
   password forgotten procedure. Note that this is a default only --