We use ASSP in the front of Zimbra with great success.
Users is training ASSP by forward e-mails to spam@assp.local and notspam@assp.local.

Is there a way to create a server-side Sieve filter to automatically forward an e-mail sent to SPAM folder (by pressing SPAM button) to spam@assp.local ?
Other way I think is to create a script that take e-mails from SPAM folder and forward them via formail or similar, but I don't know how I start.

Best regards!