Dirty Words Don’t Tell the Whole Story

Though you must carefully craft the words used in e-mail campaigns to aid deliverability, other factors, such as authentication, reputation, and message construction, are more critical if messages are to land in inboxes rather than junk folders, a virtual wastebasket.

Several e-mail industry pundits have disclosed so-called dirty words that should be avoided in messages. An extensive list of triggers that set off spam filters can also be found at SpamAssassin, an open-source spam-filter program.

If you think you solved your spam problems because you took the word “free” out of your e-mail’s subject line, think again.

You must examine behind-the-scenes factors, or you’ll be no better off.

How Content Filters Work

Many major content filters rate messages according to how many elements in them are commonly associated with spam, such as copy, format, coding, and headers.

A content filtering system doesn’t automatically flag a message because it contains one or two words associated with spam. Instead, a system like SpamAssassin runs hundreds of tests on a message, searching for spam-like elements. When the system encounters one, it assigns a point value, from a fraction for a suspect word to several points for major infractions, such as being blacklisted.

If a message accumulates too many points, the filtering system flags it as spam. Just how many points it takes to cross the threshold depends on how the filters are configured at the destination. Some are set very low, with three to five points being all that’s needed. Others are more liberal.

More issues are also likely to trigger filters and collect higher point values than those assigned to words in the message body. They include:

  • Incorrectly formatted or incomplete e-mail headers, which list technical details of the message transfer, including the sender’s IP and e-mail sending address
  • Broken tags and sloppy HTML coding
  • Too large an image relative to the amount of text
  • Scripting that could launch viruses or spyware
  • Attachments
  • URLs or domains that have appeared in spam
  • Using “free” in a subject line or “click here” in the body may add a fraction of a point to a total content score, but if other e-mail elements are in good order, the message shouldn’t be flagged as spam.

    How Concerned Should You Be?

    Most of the time, major portals such as Hotmail, Yahoo, and AOL rely more on the sender’s reputation than on message content. Even if content scores high with the filters, a good reputation should help messages get to an inbox.

    Most corporations rely on content filters to block spam. Thus, content plays a larger role in business-to-business (B2B) message delivery.

    You know your market segments. Analyze domain names in your e-mail address database, and you’ll see your major destinations.

    The Problem with “Free” and “Click Here”

    Select your words carefully when composing messages to attract the response you want from readers. Remember: innocuous content may sail through spam filters but won’t catch a reader’s eye.

    So, yes, on one hand put “free” in the subject line if you’re offering free shipping or downloads. Be more concerned it’s the right offer for your audience and conveys the right brand image.

    The same applies to “click here,” another perennial on the dirty-word list. Deploy an alternative phrase that better describes the result you want, such as “subscribe here,” “learn more,” or “buy now.” This tells readers exactly what will happen if they click.

    Test the entire message before you send it, including subject line, offer, and body copy. Test for possible blocking or filtering, and you’ll know before it’s sent if there are major red flags.

    Many delivery service provider products, such as EmailAdvisor, Pivotal Veracity, and Return Path, use Bayesian-style (define) content filters to identify issues and test message content before you pull the trigger. Most e-mail service providers (ESPs) also include this content-check feature in their applications, though usually on a more limited advice scope. You can walk the line between catchy copy that will trigger a good response and spammy copy that will set off too many filters.

    Remember, spammers move faster than cockroaches when a light goes on. Today’s dirty-word list will look different a month, even a week, from now. Stay on top of spam trends by checking your own junk folders to see how your e-mail system classifies spam-like messages. Be certain your sure-fire subject line doesn’t show up there first.

    In the end, recipients are the final arbiters. If your message looks like spam and recipients can’t tell the message is from you, they’ll click the spam button. If enough of them do that, you’ll be flagged as spam and your sender reputation will suffer, even if a content checker gives you the all-clear.

    As always, keep on delivering!

    Meet Stefan at ClickZ Specifics: E-Mail Marketing on October 2, in New York City.

    Want more e-mail marketing information? ClickZ E-Mail Reference is an archive of all our e-mail columns, organized by topic.

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