Let me explain a bit about this graph.

First, our firewall has already chopped entire countries off from being able to access our mail server. Since I don't do business outside of the US, several major spam countries like China and Korea have been denied at the firewall. This reduced our inbound spam around 50%.

Next, I've implemented Greylisting. Greylisting stops about 98% of all of the spam that would otherwise hit our user's mailboxes.

The "Rejected" item in the above graph is partly a result of this greylisting. I can safely state that 99.99% of those messages are spam. With that in mind, you can see that we are blocking a huge quantity of spam at the server. This is spam that is never even accepted. The remaining rejected are triggered by one of the various Internet spammer blacklists that we use.

The "Spam" entry in the graph is the result of Spamassassin flagging probable spam.

Despite the entry for viruses, we aren't actually doing server side virus prevention as we're 99% Linux desktops.

To compare, only around 61,000 email messages were delivered by our server after filtering. That includes all outbound mail as well.

I look forward to the day that people stop using email entirely. If spam continues to grow, that's a very strong possibility.