Last year I wrote a blog entry (Energy theft in data centers) about the fact that processing and temporarily storing the enormous amount of unsolicited email (spam) cost a lot of effort and also a lot of energy.
So by improving email security we can reduce energy usage and carbon emission.
Now McAfee has made a report on this and has calculated the energy consumed in transmitting and deleting junk email. Among the findings from the report:
• Globally, annual spam energy use totals 33 billion kilowatt-hours (KWh), or 33 terawatt hours (TWh). That’s equivalent to the electricity used in 2.4 million homes in the United States, with the same GHG emissions as 3.1 million passenger cars using two billion United States gallons of gasoline;
• Spam filtering saves 135 TWh of electricity per year. That’s like taking 13 million cars off the road;
• The average GHG emission associated with a single spam message is 0.3 grams of CO2. That’s like driving three feet (one meter) in equivalent emissions, but when multiplied by the annual volume of spam, it’s like driving around the Earth 1.6 million times;
• A year’s email at a typical medium-size business uses 50,000 KWh; more than one fifth of that annual use can be associated with spam
The full report is available for free download from McAfee.com.
Day by day email is sent from and to all kinds of clients (PC’s, laptops, Blackberry’s, IPhone’s etc.) and where the email server acts as the man in the middle. These email servers are mostly located in data centers and there they are processing, world-wide, billions of email per day. These mails are not only processed but also routed through the networks and stored in huge quantities.
Of all these billions of emails not every email is welcome. The MessageLabs Annual Security Report 2009 highlights that throughout the year 2009 “average spam levels reaching 87.7%, but with highs and lows of 90.4% in May and 73.3% in February respectively”. Resulting in 107 billion spam messages distributed globally per day on average.
Spam trend (c)MessageLabs
Take an average size of 5 kB per email and the 107 billion spam messages and on a daily basis we have 535 Terabyte of spam floating around the world and being processed and temporarily stored in data centers. For a whole year we are talking about 195 Petabyte going down the drain, rubbish being processed and stored for nothing.
According to MessageLabs by the end of 2009, 83.4% of spam originated from botnets, “Botnets are groups of semi-autonomous compromised computers that are all under the control of cyber criminal organizations. Each botnet varies in size and may contain thousands, tens of thousands, or even millions of computers that will receive instructions from command and control channels. Botnets can be very flexible and are often used for a variety of criminal activities, including distributed denial-of-service (DDoS) attacks, hosting websites and sending spam emails. Much of the remainder of spam not sent from botnets originated from compromised mail servers and webmail accounts created using CAPTCHA-breaking tools.”
How much energy usage goes behind this spam processing? Processing and temporarily storing unsolicited email in these quantities cost a lot of effort and also a lot of energy. First you must have extra equipment for this enormous volume and then you have to process it for filtering out the garbage. It is therefore not only a misusage and theft of service but also a misusage and theft of energy. Improving IT security and especially email security can help reduce energy usage.