I have Plesk 12 (haven't upgraded to 12.5 yet) on 2008 R2. I want to know if there are some obvious things to do to reduce spam that I haven't done yet. Currently I have SpamAssassin enabled and use three different DNS blacklists. MailEnable seams to complain if I use four or more. I chose these based on some research online as to popularity and their approach. I haven't done anything else. I'm not looking to achieve Gmail level cleanliness of the inbox, but I'd like to get as close as possible with the free approach. I only host for family and a few small clients as a value-add service to other things I do. What practices do you use?