Global Spam Levels in Mysterious Month-on-Month Fall

It's been reported that the total volume of global spam email that is being sent has fallen, month-on-month since the beginning of August 2010 and nobody knows why.

The fall, which you can see in the graph below, shows a steady decline from almost a quarter of a trillion messages every day to just 50 billion now.  The largest drop was seen over the Christmas period when the total volume of spam halved in just a few short days.

Security experts are warning that the lull may not last though they are at a loss to explain why the global spam levels have dropped so far and so regularly in recent months.

Around the same time two other global spam botnets also went quiet.

While we have seen global drops in spam before, it is uncommon for a drop to last so long.  It will be interesting to see if the levels rise again or if they will continue to drop for the next few months.

Update: Recent statistics by Cisco show that spam has not risen up again to pre-2011 values. The last three months of 2012 for instance have seen a spam count of less than 100 billion each, and the highest recorded number was 141 million in June 2011. After that, spam dropped considerable to around 100 billion messages per day with the lowest count recorded at 74.2 billion spam messages per day in January 2012