A lot of filters started out just as filters against spam. But over the years they’ve morphed into more general blocks against dangerous or problematic email. There’s a lot of crime and bad behavior on the internet, much of it using email as a conduit or vector. Filtering is so much more than stopping spam now. It’s as much, or more, about stopping crime.

Email filters are essential to protect us from scammers. Sometimes I forget this, and then I read about a grandmother getting swindled by a Nigerian scammer and ending up dead.

There are real consequences to poor filtering and there is real crime facilitated by email. It’s easy to forget this as we deal with the email that gets caught in filters when they shouldn’t.

Filters are one of the first lines of defense against online crime.

Not only does filtering stop crime, but they also keep email working. An unfiltered mail stream is an ugly, unreadable, unworkable mess.