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 Habeas.com, 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 PC World newsletter!

Error: Please check your email address.

Tags antispam

Our Back to Business guide highlights the best products for you to boost your productivity at home, on the road, at the office, or in the classroom.

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

Calvin Sun

Computerworld
Show Comments

Essentials

Microsoft L5V-00027 Sculpt Ergonomic Keyboard Desktop

Learn more >

Lexar® JumpDrive® S57 USB 3.0 flash drive

Learn more >

Mobile

Lexar® JumpDrive® S45 USB 3.0 flash drive 

Learn more >

Exec

Lexar® JumpDrive® C20c USB Type-C flash drive 

Learn more >

Audio-Technica ATH-ANC70 Noise Cancelling Headphones

Learn more >

Lexar® Professional 1800x microSDHC™/microSDXC™ UHS-II cards 

Learn more >

HD Pan/Tilt Wi-Fi Camera with Night Vision NC450

Learn more >

Budget

Back To Business Guide

Click for more ›

Most Popular Reviews

Latest News Articles

Resources

PCW Evaluation Team

Azadeh Williams

HP OfficeJet Pro 8730

A smarter way to print for busy small business owners, combining speedy printing with scanning and copying, making it easier to produce high quality documents and images at a touch of a button.

Andrew Grant

HP OfficeJet Pro 8730

I've had a multifunction printer in the office going on 10 years now. It was a neat bit of kit back in the day -- print, copy, scan, fax -- when printing over WiFi felt a bit like magic. It’s seen better days though and an upgrade’s well overdue. This HP OfficeJet Pro 8730 looks like it ticks all the same boxes: print, copy, scan, and fax. (Really? Does anyone fax anything any more? I guess it's good to know the facility’s there, just in case.) Printing over WiFi is more-or- less standard these days.

Ed Dawson

HP OfficeJet Pro 8730

As a freelance writer who is always on the go, I like my technology to be both efficient and effective so I can do my job well. The HP OfficeJet Pro 8730 Inkjet Printer ticks all the boxes in terms of form factor, performance and user interface.

Michael Hargreaves

Windows 10 for Business / Dell XPS 13

I’d happily recommend this touchscreen laptop and Windows 10 as a great way to get serious work done at a desk or on the road.

Aysha Strobbe

Windows 10 / HP Spectre x360

Ultimately, I think the Windows 10 environment is excellent for me as it caters for so many different uses. The inclusion of the Xbox app is also great for when you need some downtime too!

Mark Escubio

Windows 10 / Lenovo Yoga 910

For me, the Xbox Play Anywhere is a great new feature as it allows you to play your current Xbox games with higher resolutions and better graphics without forking out extra cash for another copy. Although available titles are still scarce, but I’m sure it will grow in time.

Featured Content

Latest Jobs

Don’t have an account? Sign up here

Don't have an account? Sign up now

Forgot password?