Some users do not get notifications of new spam
[BrightmailScheduler_Worker-35] [SpamNotificationManager] ERROR - Cannot notify the user that he or she has new spam messages.
com.symantec.smg.controlcenter.InvalidArgumentException: This address belongs to a distribution list. This operation is supported only for user addresses when distribution list expansion is enabled.
This occurs when you have both "Enable distribution list expansion" under Administration -> Directory Integration and "Notify distribution lists" under Spam -> Quarantine settings are enabled.
These two features can conflict with each other. To resolve the issue, disable "Notify distribution lists" under Spam -> Quarantine Settings.