Posted by Marc Powell at August 20, 2009
Filed Under: Technical
Almost everyone receives some spam to their Inbox. While it can be
annoying, what most people don't see is the amount of spam that doesn't
make it to their Inbox due to filtering. With school starting again and
folks getting back into the routine of regular e-mail use I thought I
would share with you some of the statistics we gather on the mail
system. Click the image below to see a larger version.
(More...)
We've been gathering detailed statistics since January of 2006. This allows us to see trends about overall mail volume and to gauge the effectiveness of the e-mail system overall. Messages can be classified one of three ways --
- spam - E-mail that is clearly spam and should not be delivered.
- ham - E-mail that is legitimate, or almost certainly so, and is delivered to mailboxes.
- {Spam?} - E-mail that looks spammy but without enough confidence to block it. This is delivered so that you can make your own judgement.
Since August of last year, we've seen significant increases in spam being sent to us as well as new techniques used by spammers to try to avoid filtering systems. As shown by the graph, the system has been very adept at keeping up with those changes. The amount of mail that actually reaches Inboxes, shown in green, has remained very consistent since we began gathering statistics, only increasing in relation to increased usage within schools.
In the past year, 1.39 Billion messages were sent through the system of which 1.32 Billion were blocked as spam (94.7%). Only 73 Million messages were delivered to Inboxes; a small fraction of overall mail sent. About 3 Million messages fell into the {Spam?} grey area (0.3% of all mail) and 3.1 Million viruses were found after scanning 80 Million files totaling 4.9TB of message attachments. Instances of real e-mail inappropriately blocked as spam (false positives) were practically non-existent at less than 50 incidents.
Throughout the year the Internet anti-spam community has been successful in shutting down a number of large spam-generating entities. Unfortunately, they didn't make that big of a dent, they came back online under different guises or others were there to take their place soon after. In the ongoing fight against spam, ENA continues to actively participate in the online anti-spam communities to share new spam sources and new spammer techniques as well as to learn from the experiences of others. Only through global community involvement can new threats and trends be identified and blocked.
