Dodging Spam Filters

SEMA News—May 2016


By Joe Dysart

Dodging Spam Filters

Giving Your Legitimate E-Mail the Best Chance to Get Through

  Dodging Spam Filters

While e-mail spammers are about as popular as a carnival barker at a wedding, too many of us are being unfairly characterized as spammers simply because our e-mails “look like” spam.

“Internet service providers are waging an endless war against the spammers who invade our mailboxes,” said Maciej Ossowski, director of enterprise sales for GetResponse (, an e-mail marketing service provider. “This war has heavy casualties in the form of ‘false positives’—legitimate commercial e-mails mistakenly routed by spam filters to bulk folders.”

Unfortunately, there’s no way to counter spam filters head-on. After all, spam filters are nothing more than robots. And they’re blindly programmed to characterize one e-mail as junk and another e-mail as valuable, based on the opinions—right or wrong—of the people who programmed them.

There are scores of spam filtering services across the globe, each with its own, often differing metrics as to what constitutes spam. If that’s not frustrating enough, individual companies also often put up a second line of defense against spam at their digital perimeters, throwing up their own set of digital roadblocks as to what e-mail gets through and what e-mail gets sent to never-never land.

Indeed, the only way to ensure that your e-mail or marketing message stands the best chance of leap-frogging past the sometimes onerous judgments of spam filters is to learn the logic behind how spam filters work and avoid common pitfalls, according to Ossowski and other experts on e-mail spam.

Avoid Trigger Words: While you may have perfectly legitimate reasons to use words like “free,” “buy” and “promo,” spam filters consider such words red flags. Other sales-type words to avoid include “bonus,” “purchase,” “prize” and similar hype verbiage.

Avoid Unnatural Punctuation: It’s tempting to break through all the marketing noise in people’s mailboxes by resorting to multiple exclamation points!!!!, ALL CAPS and similar tactics, but it will increase your overall spam score and increase your chances of ending up in the spam bin. Ditto for sending text in different colors.

Use Images Sparingly: Although there are perfectly legitimate reasons to embed images in e-mails, such images can increase your spam score. Indeed, some spam filters auto-route e-mails to the spam folder simply for containing a business logo signature at the close. Unfortunately, there is no cure-all to avoid such unfair treatment, since all spam filters—and all IT security persons at companies across the globe—have their own policies on how images in e-mails are treated.

Avoid Image-Only E-mails: This is a major red flag, since many spammers try to avoid the text-content checking of spam filters by sending an image of an entire page of text rather than sending the individual lettering for the message. Spam filters are wise to this ruse and often auto-route image-only e-mails to spam boxes without a second thought.

Deep-Six Dirty Tricks: Some marketers may think that they’re being clever by designing a pitch with a subject line that begins with Re:—as if it’s a response to a previous message. Others will send a marketing message with Fwd: in the subject line. And still others try inserting random characters in the subject line—such as f.o.o.led y.a—to try and throw off spam filters. Problem is, e-mail has been a mass medium since the early ’90s, so seasoned spam filters have seen this all before and often summarily auto-route such messages to the junk folder. Essentially, if you can think of a trick, chances are spam filters are already aware of it and will punish you for using it.

Code Your HTML Correctly: Experts advise sending plain, non-HTML e-mail whenever possible. But when you must use HTML mail—such as e-mails using stationary, formal layouts, images and the like—ensure that your IT person has checked the program generating your HTML-based messages and can confirm that the resulting HTML is clean.

Use Attachments Sparingly: Given that hackers infiltrate computers every day by sending innocuous-looking attachments poisoned with malware, many business people are extremely reluctant to open marketing messages that include an attachment. Ditto for everyday correspondence you’re sending to someone who doesn’t know you.

Canada Prime Minister Justin Trudeau
Canada Prime Minister Justin Trudeau oversees an anti-spam law that’s even tougher than its U.S. counterpart.

Avoid Purchasing Mailing Lists: Unfortunately, pre-packaged mailing lists often include hundreds of e-mail addresses that are no longer valid—the use of which will greatly increase your spam score, since all of those messages will bounce back to you. “Don’t buy a mailing list,” said Matthew Stibbe, CEO of Articulate (, an online marketing provider. “They’re self-evidently spam.”

Check Your IP Reputation: Free services such as WhatIsMyIPAddress BlackList Check ( will tell you your computer’s IP address and let you know if any of the major spam-checking services consider the address a spam source. It’s important to know: Your IP is essentially the address of your computer on the Internet, so if it’s blacklisted for some reason, anything you send from your computer will be seen and treated as spam by the blacklisters.

Ask to Be Whitelisted: In an ideal world, every customer who receives your marketing messages would have already whitelisted you. Essentially, whitelisting signals to a computer that messages from an e-mail address are pre-approved and should pass through a company’s spam filters, no matter what. Sender e-mail addresses can be whitelisted network-wide by your IT department or whitelisted for individual computers using preference tools in the e-mail client used to receive e-mail.

Examine Those Messages Included in E-mails Bounced Back to You: You can often get a clue about the specific reason a spam filter considers your e-mail or marketing message spam by examining the explanatory messaging that’s often included with e-mails that are bounced back to you. At the very least, if you change your e-mails based on what you learn from these bounce-backs, you’ll lower your overall spam score.

Monitor Your Deliverability: You can get a decent idea as to whether or not your e-mails are getting through spam filters by creating a number of phantom e-mail addresses on the popular free e-mail services. If you send your message to 10 phantom e-mail addresses on Yahoo Mail, AOL, Hotmail and Gmail—a total of 50 phantom e-mail addresses—and all 50 e-mails arrive, chances are your e-mails are faring well in the world’s spam filters.

Get Certified: You can get certified as a trusted sender by companies such as Return Path ( if you allow them to audit your e-mail sending practices and they can verify that you’re playing by the rules. You’ll need to be sending from a “static IP” to get such certification—an IP address for your business that remains constant. Your IT person or your Internet service provider will be able to advise you about the kind of IP you have.

Go Deeper: The more you know about how spam filters work, the easier it will be to legitimately avoid them. MailChimp offers a free, easy-to-read, in-depth guide at Your attorney will also want to read over the legislative fine print about what the U.S. government sees as spam and what penalties are in store for you if you’re caught sending spam. You can get all those details from the Can-Spam Act at Canada has its own anti-spam guide at

Joe Dysart is an Internet speaker and business consultant based in Manhattan.

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