Turn off the Anti-Spam daily notification in the Spam Quarantine settings
Create a notification template - unfortunately its only text based and this will be a per-message notification, not daily summary.
Within the Anti-Spam settings on your inbound policies, add an X-header with value, when the message is marked as Suspect Spam.
Create a Content Filter to detect the header exists and/or the value and then notify the recipient using the template.
Apply the Content Filter to the desired Inbound Mail Policies
I would also add a Message Filter that looks for and strips the X-header used above.
That way nobody can inject the header and cause a match on your rule.
Alternatively, as its Suspect Spam - add the X-header and deliver. Get the mail system to folder messages containing the X-header into the users spam folder. That way you get no calls to release.
