Email Marketing Best Practices: Avoiding Spam Filters

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When composing your marketing emails, it is important that you adhere to some best practices to help reduce the chances that your message will be flagged as spam email – which will prevent your email from being read.

Most email providers and programs have some type of spam filter enabled. Spam filters scan all received email messages looking for a long list of things that might indicate an email is spam, and use complex algorithms to determine if the email should be allowed, blocked, flagged, or sent to a separate spam folder.

Most systems use a “spam-rating” system that assign a risk-factor to its filter criteria. Every time an email matches one of the criteria, the email’s “spam-rating” goes up. Once the rating reaches a certain level, it is treated as spam.

Every spam filter uses different rules, and for security reasons they do not publish their rules, so there is no one guaranteed method for making sure your email is never accidentally identified as spam. However, there are some general rules that are effective. When creating your marketing message, always keep in mind the below information:

Words and Phrases to Avoid Using

One of the key things that spam filters look at is the text content of an email message, including both the email body and the email Subject Line. A guaranteed way to increase your spam-rating is to include words and phrases that are known to be common in actual spam messages, so it’s best to avoid these whenever possible.

The occasional use of a “spam” word is likely not enough to get your email flagged as spam, especially if the word or phrase is part of other non-spam-like text. For instance, a spam filter might identify the word “opportunity” as a potential risk. If your message body contained the sentence “This is your opportunity to tour a premium waterfront home in the Oakdale area.“, it will likely not increase the spam-rating (or if it does, not by very much).

On the other hand, having an email subject Line of “Once in a Lifetime Opportunity!” would undoubtedly increase the spam-rating. Take a look at the list below for some examples of what to avoid.

Words and Phrases to Avoid:
  • Free!
  • 50% off!
  • Click Here
  • Call now!
  • Subscribe
  • Earn $
  • Discount!
  • Eliminate Debt
  • Double your income
  • You’re a Winner!
  • Reverses Aging
  • “Hidden”
  • Information you requested
  • “Stop” or “Stops”
  • Lose Weight
  • Multi level Marketing
  • Million Dollars
  • Opportunity
  • Compare
  • Removes
  • Collect
  • Amazing
  • Cash Bonus
  • Promise You
  • Credit
  • Loans
  • Satisfaction Guaranteed
  • Serious Cash
  • Search Engine Listings
  • Act Now!
  • All New
  • All Natural
  • Avoid Bankruptcy
  • As Seen On…
  • Buy Direct
  • Casino
  • Cash
  • Consolidate Your Debt
  • Special Promotion
  • Easy Terms
  • Get Paid
  • Guarantee, Guaranteed
  • Great offer
  • Give it away, Giving it away
  • Join millions
  • Meet Singles
  • MLM
  • No cost, No fees
  • Offer
  • One time
  • Online pharmacy
  • Online marketing
  • Order Now
  • Please Read
  • Don’t Delete
  • Save up to
  • Time limited
  • Unsecured debt or credit
  • Vacation
  • ******
  • Visit our web site
  • While Supplies last
  • Why pay more?
  • Winner
  • Work at home
  • You’ve been selected

Image Content

Images can increase the aesthetics of a marketing email, communicate information, or have specific functionality (like a Sign Up Now! button). However, there are two important things to keep in mind when using images:

  1. Many email clients will not display images by default when an email is received. The recipient must select an option to allow the download/display of images before they will appear as part of the message. This is done for security reasons, as images can be used for malicious purposes.
  2. Email spam filters don’t know what is in an image, so they have no way of knowing if an image contains spam content. This means they usually choose to assign a higher spam-rating to emails that have a large number of pictures with little text content.

When using images in your email, always make sure that your main message is communicated with the text in the email, and will still make sense even without the images appearing. If you have designed an image that encourages people to click it to visit your website, make sure you also provide a text link. A good rule to follow is to make sure that at least half of your email content is text.

It is never a good idea to send an email that consists entirely of one large image, as it is almost guaranteed to be indentified as spam.

Email HTML and Text Formatting

When creating the content for your email, make sure that you avoid the use of multiple different font colors. Using one color for headers and another for your main text is perfectly acceptable. However, avoid overusing font colors, as it can increase the spam-rating. Also avoid the use of ALL CAPITAL LETTERS.

If you created your content in a word processor or webpage design program, make sure that the HTML code is cleanly formatted when you paste it into your email client. Certain programs can insert a lot of extra HTML code that is not necessary for the display of your content. Excess code can sometimes increase your spam-rating.

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