Spam in Email Marketing: How to Avoid Email Spam Filters

Spam in Email Marketing: How to Avoid Email Spam Filters!

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by Liubomyr Sirskyi
Copywriter at Kwiga

Life is full of little irritations that can make even the most patient person want to scream. From loud chewing to not using turn signals when driving, spam letters are also among the things that irritate. That's why email services have long created and embedded spam filters that save users' inboxes from being exploded with spam letters. And that's also why making your messages actually reach your subscribers' inboxes is so challenging.

So, how can you avoid spam filters and get your emails delivered? In this article, we will discuss the issue of spam in email marketing and discover the best ways to improve your letters’ credibility.

What Is Spam in Email Marketing

Spam is the term used to describe unsolicited email, which is defined as a message sent to recipients without their permission. Spam can be sent through an email marketing platform, or it can be sent manually by an individual. Spam emails aren't just annoying — they can also be dangerous. They're often full of viruses or other malware that could compromise the user's device or their personal information.

Types of email spam

  • Unsolicited commercial email (UCE). This is a type of spam that is sent to a large number of recipients with the goal of selling a product or service. Cold email marketing can serve as an example.
  • Phishing emails. Phishing emails are fraudulent emails designed to elicit personal information from their recipients. They often appear to come from legitimate organizations such as banks or credit card companies in an attempt to steal money and/or identities.
  • Malware emails. Malware emails are emails containing links to malicious software (malware). The malware may take many forms, including viruses, worms, Trojan horses, spyware, and other destructive programs.
  • Chain letters. Do you remember these letters that require you to forward them to others and receive [insert what do you want] in return? These are chain letters that are actually nothing more than a senseless prank.
  • Scam emails. Scam emails are emails with false information used to trick you into revealing confidential information or sending money.

How email spam affects email marketing campaign results?

So, what happens when your email marketing letters get into a spam folder? In a nutshell, it means destroying all your email marketing efforts since such emails are unlikely to be ever opened and read. According to a study by Return Path, emails that are delivered to the spam folder have an average read rate of only 1.5%, compared to an average read rate of 14.5% for emails delivered to the inbox. This means that when your letters are considered spam, your open rates, click-through rates, and conversion rates become significantly lower.

Why Your Emails Can Be Marked As Spam?

Now, that we have understood what email spam is and how it can affect your email campaign's ROI, let's find out the most common mistakes that make your letters marked as spam.

  • Spam–like email content. For example, using excessive capitalization and exclamation points can be a red flag for spam filters. There are also some words and expressions that may indicate that the letter is spammy.
  • Issues with email design. While there are no strict email design protocols, there are still some of the best practices your letter should follow in order not to be marked as spam. For example, if the letter contains too many images or doesn't contain plain text, it can be considered junk.
  • Poor domain and IP reputation. If domain and IP addresses have been associated with spam in the past, it increases the likelihood of getting into the spam filters.
  • Low user engagement. When the recipients aren't engaged with an email for somewhat reason and/or delete it immediately after receiving it, it can also be a signal for spam filters that email content can be junk.

How to Avoid Email Spam Filters — The Best Practices

Fortunately, avoiding email spam filters isn't that difficult. The only thing to do is to follow some easy yet effective rules while prioritizing your content quality and users' right not to engage with your letters if they don't want to. So, here is how to get your email marketing letters delivered right to prospective users' inboxes.

  • Use a reputable email service provider. Opting for Google Mail or Microsoft Outlook will be the right choice if you want to run frequent email marketing campaigns. These services are considered the most reliable while some other services may have a higher risk of being associated with spam activities.
  • Use a trusted email marketing tool as well. In addition to choosing a reliable email service, make sure you use a trusted email marketing tool, like Kwiga, for example. Our solution allows for cleaning your email list from invalid addresses, designing awesome emails for multiple use cases, and running targeted campaigns automatically.
  • Avoid spam trigger words in your letter content. There are some words that increase the risk of getting into spam filters. They include but aren't limited to «sale», «free money», «exclusive», «cash», «free access» and so on.
  • Personalize your emails. Personalized emails are the ones the users engage with better. So, delivering more personalized content in your letters is a direct way to improve user behavior patterns, as well as an open rate and conversion rate.
  • Warm up your email address before running large–scale email marketing campaigns. For instance, you can use Lemlist to start sending your letters in small portions. Otherwise, there is a high risk of getting into spam filters, especially if your email address and the website are new.
  • Include an unsubscribe link. The last and one of the most important pieces of advice is to include an unsubscribe link in your email design. The users should always have such an opportunity, plus it is also a sign that you send your letters to the subscribers only.


Spam filters are an important tool for protecting users against malicious letters but at the same time, they can prevent legitimate marketing messages from reaching the audience. Fortunately, there are some simple steps to follow and improve your email deliverability significantly. Use a reputable email service provider, avoid spam trigger words, ensure that your email content is relevant to your subscribers, and use a trusted email marketing automation solution like Kwiga!