This is regarding the email application for Linux called Evolution, not some ethereal take on natural selection.
After hours of searching the web I found how to get spam filtering working properly in Evolution. First, make sure that the Spamassassin plugin is unchecked and that the Bogofilter plugin is checked. Now make sure you have bogofilter installed – go to the terminal and type
sudo apt-get install bogofilter. You may have to restart Evolution for the new settings to take effect.
Now here’s the trick: Bogofilter needs to know what you define as spam and what you define as ham (not spam). I suggest you make a new folder and fill it with both real messages and spam messages. Mark all the genuine emails as important. Now select the all and hit
Ctrl-J or mark them as junk. It’ll move them all to the junk folder and will remember that this is what you think spam is. Now you need to go to your junk folder and select all the ones you’ve marked as important (the ham emails) and hit
Ctrl-Shift-J or mark them as not junk. It’ll now move all the good ones back.
I realise it’s really counter-intuitive but it’s the only way I’ve found to get it working. I’m not sure whether it’s OK to turn the Spamassassin plugin back on. If anyone has anything to add please let me know.