If LDAP is configured, the messages that are sent to non-existent email addresses (based on LDAP lookup) are deleted by default. If you uncheck the check box for Delete messages sent to unresolved email addresses, these messages are stored in the Spam Quarantine administrator mailbox. Only the administrators that have Full Administration rights or Manage Settings modify rights can modify this setting.
The deletion of unresolved email is disabled by default if LDAP is not configured. In that case, the option Delete messages sent to unresolved email addresses is unchecked and is grayed out.
(NOTE: If an LDAP server connection fails or LDAP settings have not been configured correctly, then quarantined messages addressed to non-existent users are consigned to the Scanner's deferred queue and the SMTP connection between Control Center and Scanner is closed, whether the Delete unresolved email check box is checked or unchecked. Once the Scanner's deferred retry or timeout limit is reached, the message bounces back to the sender.)
To forward spam messages for non-existent addresses to quarantine