We've released a few updates here only for the Linux version, while we grapple with adding these for MS Exchange.
1. Grey Listing: This stops heaps of spam and is the last spam tool in precedence. It will request for the message to be re-sent, which means forged emails won't make it through. Does delay the receiving of email by around 15 mins or sometimes more while the sending mail server resends the message.
There is a quarantine screen for grey listed emails so you can view which emails have been stopped or are in the queue to receive the retry. You can rescue an email and it's immediately delivered to the recipient.
Grey listing is turned off or on in the Settings>>Action screen and works immediately without need to restart.
2. Spam can now be quarantined or the headers marked and delivered for filtering at the client. This can be toggled via the Settings>>Action screen
3. Fix for situation where quarantine screen would remember users last search and would appear for other users.