I work for a small to medium sized company. We have about 100 mailboxes, some of which have been around for more than ten years.  As evidence that spam continues to get worse, I present the following chart from our Commtouch management console.  It shows that 1.2 million pieces of spam were blocked from our mailboxes in the past 30 days.

For those who are not familiar with Commtouch, it is an outside spam blocking service similar to Postini, now a part of Google (Postini, that is, not Commtouch). I have been using the Commtouch service for several years now and am very pleased.  In the past three years I think I can count on one hand the number of false positives that have been blocked.

If you look closely you will see that email blocked as spam is up to 96% of the total received.  Do the numbers and it averages out to 12,865 pieces of spam per mailbox per month.  Thats 428 pieces per day.  In reality, the majority of the spam goes to about 15 or 20 mailboxes that are publicly listed or that have been around the longest.  Amazing!

I pity the poor network administrator who doesn’t have some sort of spam blocking service or spam filter in place.  I can’t imagine any company today with more than a few mailboxes that hasn’t implemented filtering.  I read a recent article in Business Week in which the writer recommended that employees sort and delete their spam as it comes in.

That’s a ludicrous proposition for any business today that has more than a few employees or that has an email address that has been around for more than a few months. What a tragic waste of time for the employee and a loss of productivity for the employer.  You may be able to get along without filtering at home but not in a business.

I thought about making a list of the top spam filters in use today but know that I would miss way too many.  The categories include outside service filters, firewall filters, server-based filters, user-based filters, Unix/Linux filters and Windows filters.  I personally like Cloudmark desktop for home or personal use and hate Barracuda that my ISP uses.

I know you Tech Republic readers love to share and I love to read your comments.  What’s your favorite spam filter?   Do you have any spam filtering horror stories that we would enjoy reading?