Ultimate Guide: How To Avoid Spam Filters For Email Marketing Campaign


Spam filters are a great thing. They are intended to keep the bad guys out. It’s like having a high wall around a fortress. But sometimes, the good guys get walled out too. Then things get highly frustrating. This is the story of the average email marketer and spam filters.

It’s easy to choose to condemn the wall when it keeps an email marketer and their good marketing intentions out, but one thing is certain, it is never deliberate. After all, people are interested in whatever brings them benefits and improves their life. So, how can the email marketer with good intentions avoid spam filters in their email campaigns? How can they arrive the recipient’s inbox without being arrested and sent to spam folder prison with the utmost silence. This ultimate guide explains how to avoid the apparent “catch-all” effect that spam filters often have on email marketing campaigns.


Table of content: 


What Is Spam Email Anyway?

To understand the purpose of this article and where we are headed, we need a proper definition for spam email. Spam email or mail spam is unsolicited email sent in bulk – to innocent inboxes that know nothing about the sender or have previously refused email from the sender. It is also called junk email. Therein lies the problem with spam – it is unsolicited.

Spam has gained accelerating popularity since the early 1990s, and is a problem no email user is totally immune from. From African princess willing to share their lavish inheritance with you, to counterfeit messages that appear to come from a reliable source asking that you supply personal information. There are also simple emails from senders you do not know and unsolicited commercial emails sent in bulk to a purchased (sometimes stolen) mailing list with your email address in it.

These types of email are what spam filters scan and decide should be in the junk folder (spam folder). Sadly, genuine emails from marketers have all the elements of spam email, such as spam trigger words. You will learn how to avoid those in this guide, at least twenty different ways.

Such emails have created so much adverse impact that ReturnPath’s research says only 21% of emails sent by genuine marketers are sent to subscribers’ junk folders. This is the email marketer’s frustration; that one small error has caused near irreparable damage to their email deliverability and reputation.


How Email Message Hit Spam


To understand how to beat spam filters as an email marketer, you need to understand first the process that qualifies your email message to be sent to the spam folder. This will help you craft better targeted emails that your subscribers will see every single time.

ISPs, Email Content, and Deliverability

ISPs (Internet Service providers) always review mail servers when deciding to accept or reject a message and there are standards for excellent deliverability. The content of messages is more important than many email marketers realize and ISPs run messages through content filters to determine if they are junked or inboxed.


Spam Email Vs Phishing Email


Spam email is often confused with phishing email. Spam email however, does not always have criminal intent. What both email types share in common is their content. Phishing email leverages spam email techniques to cast their net as far as possible.

The content of phishing emails can also be tweaked appropriately to get them past spam filters.


What Is Spam Email Filtering?


Spam email filtering is the process of using email filters to catch and quarantine unsafe emails sing multiple security mechanisms. There are published blacklists of mail servers known to relay spam.


How Spam Filtering Works


Email filtering solutions use a set of protocols (rules) to determine what gets to the inbox and what gets weeded out. Filters organize email according to certain rules or criteria. They were designed initially to identify spam or send it to the spam folder. Some ESPs use email filters to categorize messages for inbox organizations.

Types of filters include:

  • gateway spam filters
  • third-party (hosted) spam filters
  • desktop spam filters


How To Report Spam Email


Because of how potentially dangerous spam is, there are several avenues to report spam email. It is not a wasted effort to report spam email as some might think it is. Apart from trusting your ISP and inbox spam folder, this is one more thing you can do. Forward unwanted  emails to your email provider stating that you are complaining about being spammed, the sender’s email provider, and other appropriate authority.

One way to do spam email detection is by checking the number recipients of that email. This can be done in addition to scanning message headlines.


How To Stop Spam Email


To stop spam from taking over your email, you can take a few steps right away:

  1. Never respond to spam.
  2. Change your email address.
  3. Hide your email address.
  4. Invest in a third-party spam filter.
  5. Train your filter.


How To Get Through Spam Filters


There is an art to get past spam filters; a rare skill indeed. But, it can be learned. To ensure your emails reach destination inbox and improve your open rate, the following tips have proven helpful:

  1. Choose a reliable email service providers (ESPs). Any good reputation they have depends on the good reputation of their clients. ESP clients delivering high-value content with high scores on their IP addresses improve the ESP’s trustworthiness.

  2. Use a recognizable sender name. Send emails from email addresses containing personal names and or brand names. This is because people prefer to open emails with personal names in the from box.

Convince and Convert says 43% of email recipients will click spam simply because of what information they see in the “from” field, name and address.

Top ESPs also watch from” field with keen interest. Using a blacklisted IP address and obscure “from” field names like 202019@yourdomain.com or noreply@yourdomain.com could cost you in terms of deliverability.

  1. Obtain third-party certification. You can tell spam filters you are not a spammer if you get sender accreditation from a third party.

These companies assess your email practices and certify that you’re a trusted sender. This ensures more inboxes tell ISP spam filters to let your emails get through.

  1. Check your IP address reputation. Your IP address reputation directly impacts your email deliverability. Tools like Multirbl. Vali and MxToolbox let you check if you are a blacklisted sender.

  2. Test your emails before sending them. Testing improves your chances of reaching subscribers’ inbox. There are many high quality spam content checkers. Mail Tester tests your email quality by mimicking spam filters and assigning a score based on spam trigger words that it finds within the email.

  3. Always be learning. Keep updating your knowledge of spam filtering technology, anti-spam law, and ISP practices. The laws are always evolving in technology as a whole. Internet marketers must know the basics of the CAN Spam Act that defines the fundamental rules for commercial email. It states requirements for commercial messages and empowers the recipient to stop you from emailing them. There are strict penalties for violation and it does not apply to bulk email alone.

Consistent learning will improve the outcomes of your triggered marketing campaigns over time.

  1. Keep email lists clean. To avoid spam traps and filters, ensure you stick to certain standards including never buying email lists.

  2. Remove hard bounces from email lists. Sender reputation is a function of bounce rates. Carefully manage your reputation to improve deliverability. Emails to inactive addresses over time are recorded by an ISP as a spam trap hit. Once you are notified of a bounce by your ISP, delete that email address.

  3. Respect your unsubscribers by ensuring they have the option to unsubscribe when they want to. A simple one-step process makes it as painless as possible.

  4. Use subject lines wisely. 69% of people mark an email as spam when the subject line SCREAMS AT THEM (whey you type it all in uppercase). Most people prefer an all lowercase headline and use single exclamation marks.

Other ways to keep your email spam score healthy include:

  • Being careful not to make false promises.
  • Avoiding rich media content like video and Flash movies.
  • Not embedding any forms, which are often a huge security risk.
  • Not including attachments
  • Using as few colors and fonts as possible.
  • Using as few images as possible.
  • Ensuring images display correctly.
  • Offering plain text and HTML versions of email.
  • Using correct spelling and grammar.
  • Sending content that fosters communication.
  • Above all, paying attention to technicalities

Spam Trigger Words


These are words that set off the alarm bells in a spam filter. Avoid these words in your emails. These words include words like promise, quote, offer, order now, open, and problem. 


Spam Traps


Major ISPs also use a type of fraud management tool called spam traps. They blacklist providers to identify spammers and block emails from them. A spam trap is an email address, only it is not for a real person and cannot be used for communication. Not cleaning your email lists regularly can set you up for the harsh effects of spam traps.



Spam email will continue to be a tool of choice for criminals as long as people increasingly communicate via email. As an email marketer, you can have multiplying success in your campaigns if you will begin to apply what is covered in this ultimate guide right away.