False Positives Equal Lost Business

Updated: August 20, 2012

It's something that anti-spam vendors don't like to talk about: the fact that their products can mistakenly nail legitimate email.

Most spam experts acknowledge that all anti-spam tools tend to occasionally tag genuine messages as junk, removing the message from recipients' view. Such occurrences are called "false positives."

Like a medical misdiagnosis, a false positive can be much more than an inconvenience. Legitimate messages that never reach their intended recipients can easily lead to confusion, anger, wasted time, hurt feelings, missed deadlines and, most importantly, incomplete business transactions. Anti-spam vendors typically promise accuracy rates in excess of 99 percent. Yet with companies' financial well-being increasingly tied to their email service, any spam filter that is less than 100 percent effective poses a serious risk.

Businesses in certain industries, such as mortgage and banking, are particularly vulnerable to false positives since so many spam messages relate to mortgage- and financial-related schemes. Yet any company that uses anti-spam technology can expect that at least some legitimate messages will be incorrectly categorized as spam.

What Should You Do?

In a perfect world, there would be no need for spam filters. Yet, with a 2007 Barracuda Networks study showing that upward of 95 percent of all email is now spam, it's obvious that some type of anti-spam technology is necessary. Running a company email system without spam filters risks forcing employees to waste precious time searching for real business messages embedded in an endless stream of con offers, pornographic ads and just plain gibberish. For many companies, that's almost as unacceptable as losing good email.

Fortunately, it's possible to use spam filters while minimizing the risk of losing legitimate email; here are a few steps that your company can take.

Compare products. All spam filters aren't equal. Some products do a much better job of separating junk from legitimate emails than others. Carefully read the reviews of competing products to see which products and services offer the best filtering success rates.

Customize the filter. Just about all anti-spam applications allow administrators to fine-tune system settings for maximum effectiveness. Filter adjustment, however, is as much an art as it is a science. It's important to think creatively about words and conditions that may cause the anti-spam app to tag a legitimate message as junk. Filters for a medically oriented company, for instance, should be configured so that the word "breast" would not be blocked when followed by the words "cancer research." It takes a lot of work to tune a spam filter for maximum effectiveness.

Enable whitelisting. Whitelists allow all emails from trusted senders to pass through the filter untouched, even if they contravene filter settings. Find an anti-spam app that lets end users build and manage their own whitelists, then show everyone how to use this valuable feature.

Protect employee email addresses. Your business will get far less junk email if employee addresses aren't scattered all over the Web, where spam robots can scoop them up and relay them to spammers. Make it a company policy to prohibit employees from posting business-domain email addresses to Web boards, social networks and similar sites. Some companies take this practice to the next level by eliminating all employee addresses from enterprise Web sites, funneling viewer inquiries to specific, generic addresses such as "info@ ... " "sales@ ... " and "support@ ... "

Encourage end users to occasionally check their junk-mail folder. Most anti-spam apps dump tagged messages into a file called the "junk-mail folder," "spam folder" or something similar. Remind employees that if an important, expected email fails to arrive, a quick glance in the junk-mail bin might be a good idea.