Spam Volume Statistics

In 1999, CAUBE.AU conducted a spam survey, and is in the process of conducting another one based on addresses created in 2001. This page contains some interesting statistical observations on the volume of spam based on spams sent to addresses in the survey. The 1999 survey involved 41 email addresses which received spam in the period measured, and the 2001 survey involves 70 email addresses receiving spam in the period measured. Most addresses only appeared once - either on a web page, in a newsgroup posting, or (for the 1999 survey) in a domain name database.

The following table shows the number of spams received per address over time:

The figures shown here differ from previous graphs from the survey because these graphs involve only addresses seeded into public areas by CAUBE.AU - this omits spamtrap addresses forwarded by other parties, as well as addresses spammers simply made up - most notably, "webmaster@" for the domains seeded (no addresses of "webmaster" were seeded - this was caused by spammers taking existing domain names and assuming that "webmaster" is a valid address at any domain).

In 2002, we started seeing recipient addresses showing that spammers assume that if an address ending in a number exists at a domain, then the address also exists with lower numbers. In other words, if you have an address ending in a number because the address is a popular one, you are likely to get spam even if your address never appears anywhere public. Figures for these addresses have not been removed from the graphs below, but have been removed for the tabular statistics above.

The figures for the graphs below were collected on January 10^th, 2002, and begin on January 11^th, 2000.

Total Spams by Year for the 1999 Survey

This graph shows that the volume of spam received at the addresses in the 1999 survey increased by a factor of 6  in 2001. This correlates well with figures for the same period produced by SurfControl and Gartner Group from independant raw data. Imagine having 6 times your current volume of daily spam a year from now. This is equivalent to doubling the volume of spam received every four and a half months. The increase for 2002 was proportionally smaller, but still of significant concern at a factor of 3½, for a total increase by a factor of 21 over the two year period.

Total Spams by Quarter

1999 Survey

2001  Survey

Total Spams by Week

The first time we published volume statistics the weekly figures tended to fluctuate too much to provide a useful graph - this is no longer the case as you can see below. Other than a short period in 2002, the volume has been fairly consistently up.

1999 Survey

2001 Survey