After installing SpamAssassin last March, the spam on my 7-user server dropped from roughly 80-100/week to one or two a month.
So it’s not a big surprise that e-mail marketing firms are getting nervous, starting with a smear campaign against SpamAssassin. Gord Sears’s column in his marketing newsletter calls it a violation of free speech, demanding a law against server-side filtering software. Paul Myers, in his You HAD Mail column on Talkbiz.com, claims that SpamAssassin could bounce valuable mail like “discussion list posts,” “newsletters that you requested,” and “LOTS of personal emails from friends and family.”
I want to clear up a couple misunderstandings: First, the recommended SpamAssassin configuration flags e-mail as spam before forwarding it to the user, allowing for simple filtering in the client. It doesn’t delete the mail, although you can configure procmail that way, if you like. Any ISP that quietly deleted e-mail without consent wouldn’t be very popular for long.
Second, Spam Assassin has to be tailored for the individual. For the first week after installation, I had to add a few newsletters and discussion lists to the “whitelist,” which tells Spam Assassin never to filter e-mails with a particular “From” address or subject. After that, Spam Assassin very rarely accidentally flagged good e-mail as spam. And it has never once mistakenly flagged an e-mail from someone I know as spam.
It’s not a perfect system, but it’s a depressing necessity.