Email filters are wonderful things… Until you sit on the publisher’s end of the filter, that is.

If you’re sending out a newsletter, you need to be concerned about your reader’s filters.

While there’s no method that’s 100% fail-proof, a little education can go along way to keeping your newsletter out of the majority of your reader’s filters.

What are Spam filters?

Your readers may have an ISP-installed filter (like Spam Assassin or Cloudmark), or they may use a program like Clear My Mail.

Either way, many of the available filters use a points-based system to determine whether or not a specific piece of email is Spam.

Your email message receives points for certain words, phrases, design elements, and color schemes.

You can also lose points (good, in this case) for meeting other criteria, such as belonging to a certain domain, having SPF records, or sending multi-part MIME email (instead of straight HTML).

Some systems also use user networks to determine whether or not an email message is Spam. Users can typically also submit specific domains from which they receive a great deal of Spam to be blocked.

Typically, these domains are placed on a blacklist.

Blacklists are primarily compiled by volunteers based on emails submitted by the general public. In other words, when you receive a message you believe is Spam, you can email it to them and they may place the sender on a blacklist.

Because most filters use a mixture of human effort (such as the blacklists) and computer matching (such as the point-based scoring), you’ll want to look at your newsletter accordingly and consider both the human and computer elements.

Looking Legitimate to Readers

• Be consistent. Readers are more likely to suspect a newsletter is Spam if they haven’t received it for awhile. By setting a consistent schedule, your readers are more likely to be familiar with it.
• Keep your promises. Clearly explain your newsletter on your subscribe form (tell readers what you cover and how often you publish, at least), and make sure to honor your reader’s expectations.
• Be professional and polite. Don’t type all in capital letters (and don’t type without any capitalization at all), and be careful with your spelling and grammar. You might also start your newsletter with a letter from the editor.
• Create a reassuring masthead. Your masthead should include subscribing and unsubscribing instructions. Also include a contact in case they have any trouble subscribing or unsubscribing.
• Never send it unsolicited. But, of course, you already knew that.

Convincing the Computers

• Use the right language. For instance, you may be better off writing unsubscribe instead of remove. It may sound trivial, but since most computer-based filters are based on a point system, each word you use needs to be carefully chosen.
• Stay far, far away from subject lines that scream Spam. You know these well—they’re the ones that cause you to delete an email unread. Simply apply your rules for reading subject lines to writing them. Filters assign higher point values (remember, points are bad) for Spammy words in subject lines because of the importance of subject lines in getting an email message opened.
• Don’t send attachments. Not only does the typical reader regard attachments with suspicion, but some filters dump an email with an attachment, especially when they’re set up to screen out adult material and viruses.
• Use a reputable company for distribution. If you’re not sending the email from your own domain, make sure to check out the company you send it with. Remember, filters often use blacklists that may block entire domain names; you don’t want to send your newsletter from a domain that’s blocked.
• Send both HTML and plain text versions. If you publish a newsletter in HTML, make sure you send each issue in a multi-part MIME format. When an HTML email message includes a plain text version, the filters typically reduce the points the message has accumulated.
• Stay away from the wrong color schemes and design elements. Take a look at some of the Spam in your inbox and you’ll notice trends. Lately, I’ve been seeing a lot of embedded images (instead of linked images). I also see lots of red and green text and black backgrounds. The filters notice these trends and often add extra points for Spammy design elements. They also often add points for unknown HTML color codes, so you’re best off sticking with a web safe palette for email newsletters.
• Use a tool to check your newsletter.SpamDance offers a copy and paste form to see how many points your newsletter has accumulated. You can also use SiteSell’s system which has you mail in the newsletter. By running each issue through a filter like one of these, you’ll be able to fix problems before you click send.

Rather than complaining about declining delivery rates, be proactive. Learn how you can get your newsletter delivered by following these steps and staying up-to-date with the latest delivery trends.

By keeping up-to-date on all the latest changes to filters, you may discover the filters can actually be your allies. They keep you honest; they keep you creative; and, even better, they reduce the competition for your reader’s time.