I had a few problems with this plugin, I didnt do a ticket as I am not the licence holder but I will be happy to discuss this with the dev to help to resolve it. The issue I have fixed myself but what happened is below.
It initially threw up an error in DA on installation about missed ixed libraries, the 4.4 version is not bundled dispite php 4.4.x now been months old. I think this is a simple fix guys and a bit careless for a commercial product as I believe this error caused the remaining problems I had.
I then installed the ixed libraries and a new error comes up about the licence been invalid, I looked around in DA but no where to enter it so I hunt in ssh for a manual way to enter the licence. The file it seems I need to edit doesnt exist, so I guess that because of the ixed problem installation is incomplete.
I then ran the install.sh from the scripts dir which seemed to install the missing files. I then manually entered the licence in ssh, I then got a error that it couldnt contact the licence servers but there was connectivity, the actul fault was a space at the end of the licence number and when removed it worked. So perhaps the error can be more accurate for this problem as well.
After this the plugin appears to be working. I will report if I find any more problems.
A question tho as I am curious, spamassassin uses many advanced filtering to catch spam such as looking for special words in the body and subject and contacting dcc servers. Does spamblocker solely rely on spam blacklists sorbs etc. or does it have its own filtering techniques as well?