I hope you did the homework I assigned last week. I wanted you to find out:

• What your data services cost per month.

• What percentage of your available WAN bandwidth actually is used.

• What percentage of that bandwidth is used for e-mail.

• What storage costs you.

• How much mail your users send and receive each day.

• How much spam each user gets each day.

• How long it takes a user to deal with a single piece of spam.

Those were the basics. To complete this exercise you'll also need to know the average fully burdened cost of an employee (taking into account insurance, tax, benefits, etc.). Now divide that by the average number of work hours per year to find the fully burdened average employee hourly cost.

For my calculations, I'll use some averages derived from a number of sources that might or might not be consistent with the values for your operation.

First we'll calculate productivity costs. If the average user (working 220 days per year at a fully burdened annual cost of $71,440) receives 100 messages per day of which 30% are spam and the average time required to handle a piece of spam is 5 seconds, then the average cost to handle spam per user, per day, is $1.69.

This means that for 1,000 users the total cost of productivity loss per annum will be (hold on to your seats) $372,083 or $372 per employee! But while productivity loss is by far your biggest cost, the others are nothing to sniff at.

If the cost of Internet connectivity per month runs to, say, $6,000 (servicing internal users and telecommuters and mobile workers) and e-mail uses 75% of the bandwidth and spam uses 30% of that, the total cost of bandwidth used by spam (spamwidth?) per year will be $16,200.

Next, if the average message size is 50K bytes and the cost of storage per month, per gigabyte, (including management costs) is 50 cents, then it will cost $9,000 per year to store spam.

Finally, support costs: Assuming the average cost of support per user, per year, is $250 and 5% of that can be allocated to solving spam-related issues, we'll be spending $13 per user, per year, for a total of $12,500 per annum.

If we add all of these annual costs - connectivity at $16,200, storage at $9,000, support at $12,500 and the big one, productivity, at $372,083 - we get a total cost of spam per year for a 1,000-seat operation of $409,783! That is more than $409 per employee!