events: discard notification if user has empty email (cherry-pick #8938) (#8951)

events: discard notification if user has empty email (#8938)

Signed-off-by: Jens Langhammer <jens@goauthentik.io>
Co-authored-by: Jens L <jens@goauthentik.io>

authentik/events/models.py

@@ -451,6 +451,13 @@ class NotificationTransport(SerializerModel):
 
     def send_email(self, notification: "Notification") -> list[str]:
         """Send notification via global email configuration"""
+        if notification.user.email.strip() == "":
+            LOGGER.info(
+                "Discarding notification as user has no email address",
+                user=notification.user,
+                notification=notification,
+            )
+            return None
         subject_prefix = "authentik Notification: "
         context = {
             "key_value": {