eMail Industry Statistics

Email Sizes

The arithmetical average message size in the inbox of an employee is around 10KB. However:


  • The vast majority of messages are around 5KB
  • Around 10% of messages are in the 100K-1MB range. Eg, typical Word or Excel attachment
  • Around 5% are bigger than 1MB. Eg, large PowerPoint attachment, pictures of cats

The Cost of Spam, 2009


We estimate spam will cost a total of $130 billion worldwide, of which $42 billion is in the U.S. alone. That's a 30% increase over our 2007 estimates, which themselves were a 100% increase over our 2005 figures. So the growth in the cost of spam is slowing down.

This uses the same methodology as our 2005 Spam Cost report. The main components of the cost are:

  • Productivity loss from inspecting and deleting spam that gets missed by spam control products (false negatives)
  • Productivity loss from searching for legitimate email deleted in error by spam control products (false positives)
  • Operations and helpdesk running costs

Miscellaneous Statistics


  • # non-spam emails sent during 2006 by business email users: 6 trillion
  • Estimated number of non-spam email messages sent worldwide each day 2006: 25 billion
  • % of email messages sent daily that are spam messages: > 75%
  • Typical # Internet emails sent and received by a business user: 600 per week
  • Cost of a user deleting a spam message: $0.04
  • Cost of a user retrieving a bona fide message erroneously deleted as spam ("false positive"): $3.50

The World's Largest Email Systems

Here's our estimate of the world's largest email systems, measured in number of active mailboxes, as of 10/05. By "active" we mean: has been accessed at least once over the last 30 days:


Organization Seats
Sun * 150
OpenWave * 100
Hotmail 100
Microsoft 100
Critical Path * 60
AOL ** 80
Yahoo 40
IBM Notes/Domino 25
Google Gmail 20
Novell GroupWise 10

* indicates a vendor that specializes in selling to service providers
** Includes free seats

It's hard to have much certainty about these figures. Almost all vendors severely exaggerate with the statistics they hand out. This is our overall sense of real deployed seats.

Total Email Security Market Revenues, 2005-2010
Source: Ferris Research, The Email Security Market, 2005-2010


Email security revenues will continue to climb, leveling off at around $5 billion as the market becomes saturated. Figures are in millions of dollars.

Total Email Security Users, 2005-2010
Source: Ferris Research, The Email Security Market, 2005-2010


User counts are dominated by the popularity of software and appliances in ISP offerings. Figures are in millions of users.

Business Email Users, 2005-2010


2005 2006 2007 2008 2009 2010
North America 125.2 128.7 132.4 136.0 139.8 143.6
Europe 162.6 179.8 196.5 212.8 228.6 244.1
Other Americas 179.1 191.9 204.7 217.4 230.2 243.0
Africa 16.0 19.5 23.0 26.6 30.1 33.7
Asia (incl. Mid-East) 182.8 198.3 213.6 229.0 244.3 259.6
Oceania 8.7 9.1 9.5 9.9 10.4 10.8
Total 674.2 727.3 779.7 831.7 883.3 934.8

Source: Ferris Research, The Email Security Market, 2005-2010

Figures are in millions of users, rounded to the nearest 100,000.

Microsoft Exchange Operations Statistics.
Typical number of email servers supported per messaging administrator: 10-15 servers in the Exchange 5.5 world. With Exchange 2000 and 2003 that number can be significantly decreased due to multiple databases per server.With the advent of multiple databases per server in the Exchange environment, we suggest that the statistic of choice should be number of users per administrator. Typical figures are 2,000-5,000 users per administrator.



  • Typically administrators also do second tier messaging client support
  • Administrators are typically "messaging/collaboration" focused -- not just Exchange. Often they also support SharePoint, Blackberry, Active Sync, Exchange 2003, anti-spam/virus, etc
  • Administrators often administer other products in a limited fashion
  • The tasks they perform are getting diluted from "pure" messaging due to the huge overlap with ActiveDirectory. They shouldperform tasks like regular log checking, message store optimization, performance monitoring and troubleshooting. Simple account provisioning has probably been consolidated in larger enterprises