Email appliance not discarding messages from domains on Block list

Hi all,

We're running a Sophos Email Appliance ES 1100 (software version 3.8.0.2).

We have quite a substantial list of spam domains which we've blacklisted over the years.

I've added these domains to the Block list on the Sophos appliance, and the action is set to 'Discard' rather than Quarantine, however I've noticed that a lot of mail from domains on the block list is still ending up in Quarantine instead of being automatically discarded.

Is there any reason for this? In the Block list I just have the domain name, for example pur3.net, does it  perhaps need a *. in front of it?

Would be interested to see if anyone else has experienced this behaviour on this machine.

Thanks for any input :)