Spam filters: Making them work

Here are eight ways to get more out of your e-mail watchdog.

5. Choose blacklists and reputation lists wisely. Jennings points out that many spam filters let the customer choose which blacklist, if any, to use. If your organization relies on a blacklist to stop spam, he recommends that you check the management policies of the lists. Briggs notes that some are driven purely by user complaints, so relying on them will invariably lead to false positives.

6. Make sure you're not a spammer. If spam goes out from your systems, even unintentionally, it can hurt your reputation and increase the likelihood that you'll end up on spam blacklists. If your e-mail address appears in the "from" line of enough spam, Jennings says, your reputation may suffer to the point that you will have trouble sending legitimate e-mail.

A three-pronged approach will help keep your reputation intact:

  • Curb your users' questionable Web browsing, suggests Stephen Pao, vice president of product management at security vendor Barracuda Networks . If users visit dangerous or objectionable sites, malware from those sites could be installed on their computers, which could then be used to send spam.

  • Stay up to date with security patches and virus and malware definitions to ensure that spammers can't take over your systems and use them to send spam, Pao says.

  • Use outbound filtering to make absolutely sure no spam is being sent from your systems, Jennings suggests.

7. Check your own spam reputation. If your organization is on a blacklist, your recipients might not receive your outgoing e-mail. Lochart recommends regularly checking your own reputation by visiting sites such as, which provides companies with a free reputation check and helps them manage their online reputations.

If you find your company unjustifiably on such a list, Lochart suggests that you contact its administrator to voice your concerns. But getting "un-blacklisted" can be difficult.

8. Warn users to be wary of red-flag words. In sending e-mail, avoid words that are associated with spam, says Lucio Gonzalez, a systems specialist and e-mail administrator at South Texas College in McAllen, Texas. These include hey , hello , free , enlarge , pharmacy , alert and diploma.

Conversely, try to include recipient-specific information in your messages, such as project names or personal references unique to your recipient. Doing so can lessen the chance that Bayesian analysis of your message will cause it to be flagged.

By reducing false positives, you help ensure that real e-mail from your senders actually gets to you and that real e-mail from you actually gets to them.

Join the newsletter!

Error: Please check your email address.
Rocket to Success - Your 10 Tips for Smarter ERP System Selection

Tags antispam

Keep up with the latest tech news, reviews and previews by subscribing to the Good Gear Guide newsletter.

Calvin Sun

Show Comments

Most Popular Reviews

Latest Articles


PCW Evaluation Team

Sarah Ieroianni

Brother QL-820NWB Professional Label Printer

The print quality also does not disappoint, it’s clear, bold, doesn’t smudge and the text is perfectly sized.

Ratchada Dunn

Sharp PN-40TC1 Huddle Board

The Huddle Board’s built in program; Sharp Touch Viewing software allows us to easily manipulate and edit our documents (jpegs and PDFs) all at the same time on the dashboard.

George Khoury

Sharp PN-40TC1 Huddle Board

The biggest perks for me would be that it comes with easy to use and comprehensive programs that make the collaboration process a whole lot more intuitive and organic

David Coyle

Brother PocketJet PJ-773 A4 Portable Thermal Printer

I rate the printer as a 5 out of 5 stars as it has been able to fit seamlessly into my busy and mobile lifestyle.

Kurt Hegetschweiler

Brother PocketJet PJ-773 A4 Portable Thermal Printer

It’s perfect for mobile workers. Just take it out — it’s small enough to sit anywhere — turn it on, load a sheet of paper, and start printing.

Matthew Stivala

HP OfficeJet 250 Mobile Printer

The HP OfficeJet 250 Mobile Printer is a great device that fits perfectly into my fast paced and mobile lifestyle. My first impression of the printer itself was how incredibly compact and sleek the device was.

Featured Content

Latest Jobs

Don’t have an account? Sign up here

Don't have an account? Sign up now

Forgot password?