6 Strategies for Using Suppression Lists to Boost Email Performance

Victoria Berezhetska
Content Lead
9 minute read
Victoria Berezhetska
Content Lead
9 minute read

Marketing professionals are no strangers to using sophisticated targeting capabilities to deliver highly personalized messages and content to prospects and email subscribers. That is frequently based on a large amount of actionable data businesses capture about each recipient.

Today, businesses have turned targeting into a science, utilizing various email marketing strategies, campaign performance analytics, and email suppression lists to demonstrate the value that email marketing can deliver.

It all started with a simple name personalization. Then it gradually evolved into delivering marketing content based on customers’ purchasing history, web page visits, and other behaviors that help brands identify every user’s stage of the customer journey.

But while lists of contact information fitting the target audience are critical to the success of your email marketing endeavors, it is also necessary to create lists of customers who wish to refrain from receiving email content from your brand.

There’s no denying that it’s crucial to stop sending emails your customers don’t want to receive. Therefore, creating and utilizing email suppression lists can help you stop putting your email compliance and integrity at risk.

This article will examine the suppression list meaning and how creating email suppression lists can help brands maintain email hygiene, extract more value from email campaigns, and enhance their email marketing strategies.

What Is a Suppression List?

An email suppression list is a list of customer contacts who opted out of receiving marketing communication from your brand. Sending emails to recipients who willingly opted out may harm your sending reputation and deliverability rates.

On top of that, suppression lists help businesses reduce bounce rates and keep their outbound email servers from being flagged as spam.

The CAN-SPAM Act requires companies and email marketing platforms to maintain and practice email list suppression for opt-out recipients. As a rule, invalid, blocked, or bounced emails are also added to the suppression list.

Businesses often use suppression list management solutions to get more out of their email marketing efforts. Implementing an all-in-one marketing automation solution like Phonexa can be an excellent choice for small businesses and enterprises looking to reinvent the customer journey, boost email campaign performance, maintain brand visibility, and eliminate customer frustration.

Brands equipped with Opt-Intel – Phonexa’s solution for suppression list management and email cleansing – can secure their compliance, achieve more with automation, refine their email marketing strategies, and streamline their email suppression lists.

Here are some features Phonexa’s Opt-Intel offers to businesses of all stripes:

  • Automated data transfer: Share relevant data with your partners, whether they are networks, agencies, performance marketers, or advertisers.
  • Protected list sharing: Use a reliable method to maintain control over email visibility and start sharing your email suppression lists with partners and third parties.
  • Compliance updates and notifications: Eliminate compliance concerns and associated frustration. Enjoy regular notifications and updates that will keep you informed of any violations committed by your business.

How Email Suppression Lists Work

Utilizing an email suppression list helps to safeguard your sending reputation. Businesses can automatically add email addresses to a suppression list when a consumer clicks on the unsubscribe link, fills out the form on the dedicated page or marks the email as spam.

When your company launches an email campaign, the algorithm checks and matches the recipients’ email addresses to those on the suppression list. If the email addresses match, newsletters and other promotional content will not be emailed to those customers.

Simply put, brands can’t email users who have opted out on purpose or accidentally. Otherwise, email providers are more likely to bounce all of their emails, making it challenging to deliver their marketing communications in the future.

Let’s take a closer look at what email types and contact information suppression lists typically include. Here are some of them:

  • Unsubscribed contacts: These recipients unsubscribed from your emails. Such email addresses are usually added to a suppression list right away. The list then instructs your email platform or program to stop emailing those contacts.
  • Spam complaints: These are addresses that mark your messages as spam. Emailing customers after they have filed a spam complaint can damage your sending reputation. It notifies ISPs that your company sent unsolicited emails and ignored your recipients’ preferences. That could result in your company’s IP address or domain being blacklisted. Securing your email domain with DMARC is one way to avoid this.
  • Blocked, invalid, or bounced addresses: Suppression lists typically include emails that bounce, are blocked, or are invalid. Suppose a business continues to send promotional content to these addresses. In that case, its deliverability rate will suffer, signaling to ISPs that the company doesn’t try to keep its contact list clean. As a result, it can be considered an untrustworthy sender.

How To Use Suppression Lists in Email Marketing

Many businesses and marketing professionals incorporate suppression file management into their email marketing and audience targeting strategy.

It’s common to use de-targeting as a part of an overall strategy for a specific group of customers from a larger audience. Sometimes, it helps to handle targeting more efficiently via suppression files instead of positive targeting.

Another similar example is how marketers use negative keywords in their search marketing initiatives, and it helps to actively remove specific prospective recipients from a campaign’s target list.

While suppression lists can be used in various ways to optimize targeting efforts, there are also several advanced ways businesses can use suppression lists in their email marketing strategies to deliver an elevated experience for their clients.

Manage the Frequency of Email Campaigns

The frequency of email campaigns can be overwhelming, resulting in significant customer frustration. That’s one of the reasons why email campaigns may experience a significant decrease in open and deliverability rates during the holiday season.

More often than not, the ability to deliver customers a better holiday experience implies asking whether they want to opt out of emails dedicated to specific holidays or reduce their frequency.

But don’t be alarmed. In this case, customers and prospects would only partially unsubscribe from your marketing communication. Instead, they would be added to a suppression list for specific months, instructing your email platform to refrain from emailing these contacts for the foreseeable future. Then, when the holidays are over, you can resume emailing these customers.

Create Lists by Content Type

Imagine that your audience enjoys receiving your weekly newsletter but wants to avoid receiving an update on your daily deals. In this case, customers can unsubscribe from the daily deals while still receiving the weekly newsletter if you make sure that such an option is available in the preference center.

Make Product-specific Suppression Lists

It’s common for businesses to create product-related emails, and suppression lists can enable your customers to receive only emails about the products they want or own. In other words, all other emails could be opted out of and added to a suppression list explicitly created for the product type.

Use Custom Suppression Lists To Boost Customer Retention

It’s no secret that establishing a loyal customer base is one of the most reliable and consistent ways to maintain a healthy ROI ratio. Happy and loyal customers are 14 times more likely to purchase from your brand than new ones. That means customer loyalty can increase your retention rate by 5%, resulting in 95% higher profits.

Existing customers are the essential pillars of any brand, so it is in your best interest to continue marketing to them effectively. Besides, this approach is less expensive because you already know and understand them and have their contact information, including emails.

However, remember that your customers are not homogeneous and have diverse habits and interests. With custom suppression lists, you can target each group and provide them with relevant content.

Leverage the Segmentation of Suppression Lists

Email suppression lists can be divided into separate lists for each target group. While sending the correct email to the right target audience is essential, ensuring that your clients receive appropriate email content is critical for every brand.

For instance, if you provide an email service, like a subscription, and launch an aggressive ad campaign to bring in new subscribers, it’s crucial to send emails to customers who have not yet subscribed. If you email prospects or customers who have already subscribed, you risk losing their trust.

Therefore, suppression lists can help businesses ensure that every audience segment receives appropriate marketing content.

Here are some custom lists businesses can create to leverage segmentation and boost campaign performance:


Unengaged list

This list allows filtering customers who are no longer interested in your email content and have not been active for some time. Since they are less inclined to open and read your emails, creating a custom suppression list can be an excellent choice to avoid sending them your traditional emails and only send them content to re-engage and pique their interest.

Persona suppression list

Persona profiles help to determine what content your clients will engage with and want to receive from your brand. Therefore, using personas and creating custom suppression lists based on the group’s interest can help you filter out unnecessary emails for specific campaigns.

Geographic suppression list

Businesses with products and services in multiple countries typically segment their email content based on customers’ geographic location. Since product availability, languages, and income level differ by region, segmenting suppression lists by geographic location can help you target your customers more accurately.

Unqualified leads list

It’s no secret that a portion of registered emails typically doesn’t meet your requirements for prospective clients or customer base. Identifying and adding these contacts to a suppression list can help you save time and effort.


Deal With Low-value Prospects and Non-responders

Some contacts on your email list can become inactive over time, and some customers can lose interest, while others may never have subscribed. To save money and time on these customers, you must add them to a suppression list.

Naturally, having an extensive contact list is beneficial for brands. But it’s also crucial to remember that non-responders can impact metrics and ROI. A non-responder is a bogus statistic; they increase the total number of consumers you intend to reach but never accomplish a sale. That means your business will probably need help meeting its marketing objectives.

Wrapping Up

Brands and marketing experts that want to improve their email marketing efforts need to implement a suppression list management solution to increase sales, optimize each email campaign, and ensure compliance.

Learn more about how Phonexa’s Opt-Intel can help your business centralize and automate its email suppression lists by scheduling a consultation with one of our experts.

Frequently Asked Questions

Why is it important to use suppression lists?

Businesses use email suppression lists primarily to ensure that they comply with the CAN-SPAM Act, granting recipients the option to unsubscribe. As a result, companies provide a more satisfying experience for the subscribers and customers and secure a higher email deliverability rate.

Ultimately, using suppression lists could result in significantly improved deliverability and greater control over the frequency and content of messages.

How long do addresses stay on the suppression lists?

Email addresses can be listed on the suppression list for varying amounts of time. In some cases, they can have a short lifespan, from minutes to hours, while others have a longer lifespan or can even be permanent. It is generally determined by the type of rejection returned by the client’s mail server.

Can I email a customer who has unsubscribed?

If a client has unsubscribed from all communications with your business, you may face legal ramifications if you keep sending promotional content via email. Most email marketing platforms do not allow sending follow-up or additional emails to contacts who opted out.

Got Questions?

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Victoria Berezhetska avatar
Victoria Berezhetska
Content Lead

Victoria Berezhetska is a Content Lead at Phonexa. She has a Bachelor of Science degree in Business Administration, with extensive working experience as a PR specialist and content writer. In her work at Phonexa, she covers diverse topics around digital marketing, including affiliate marketing, call tracking, lead generation, marketing automation, and so much more.

Education: City University of Seattle

Expertise: Affiliate marketing, digital marketing, call tracking, lead generation, insurance


  • 8+ years of experience in digital marketing, specializing in building customer loyalty

  • Deep B2B and B2C content expertise intertwined with strong analytical and interpersonal skills

  • Unwavering drive for growth and commitment to creating impactful content

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