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How to Get Off an Email Blacklist, and Stay Off

Chad S. White
Head of Strategic Research

Having your email IP address or domain added to an email blacklist can seriously affect your deliverability, and therefore the profitability of your email program. This is doubly true if you’re blacklisted during one of your key selling seasons.

For those reasons, it’s important to routinely check if your brand is on any email blacklists and, if it is, to take the necessary steps to get removed and then to make changes so it’s less likely to end up on an email blacklist again. However, before we discuss that process, let’s make sure we’re clear about...

What an Email Blacklist Is

Email blacklists are lists of IP addresses that have been identified as sending spam and URLs that spam emails have been known to drive traffic to. These lists are maintained by anti-spam groups and independent operators and shared with inbox providers and corporations that manage their own email servers so they can more effectively block spam.

While there are literally hundreds of email blacklists, some of the more prominent ones are:

IP-Based Blacklists:

Domain-Based Blacklists:

“The impact of a blacklist is measured by the number and size of the mailbox providers who use it to protect their networks,” explains Clea Moore, Director of Deliverability Strategy at Oracle Marketing Cloud Consulting (OMCC). “The blacklist with the most dramatic impact is Spamhaus, because many of the largest mailbox providers—including Outlook.com, Yahoo Mail, and Gmail—trust it to help them make blocking decisions. For any B2C sender, being blacklisted by Spamhaus can impact upwards of 80% of their list, so you're basically dead-in-the-water.”

“How important the other blacklists are depends on the makeup of your subscriber list,” says Kent McGovern, Senior Strategic Consultant of Deliverability Services at OMCC. “For example,” he says, “B2B brands will likely suffer a bigger impact from being blacklisted by Cloudmark CSI or Proofpoint SORBS.”

How Can I Find Out If I’m on an Email Blacklist?

In addition to checking directly with the major email blacklists above, here are some tools that can check if your IP address or URL has been flagged by an email blacklist:

“Keep in mind that these tools will generally check every available blacklist to see if you are listed,” says Moore. “It's very common to run a check and see a listing or two for a very small blacklist that will have no impact on your mail. However, these smaller listings may be an important signal that you need to button up your list hygiene practices before you get into trouble with more impactful blacklists.”

How Can I Get Removed from an Email Blacklist?

Sometimes it’s as simple as just requesting that your IP address be removed. Other times you will need to work with the blacklist operator and satisfy them that you’ve addressed the behavior that got you on their radar.

Some brands may find this difficult to swallow. They might say to themselves, I haven’t broken the law. This is extortion! This blacklist doesn’t have the right to have my emails blocked and hurt my business. 

Well, they do have the right—just like Gmail and other inbox providers have the right to block emails from senders they feel are sending malicious or unwanted email. You can either play by the rules established by blacklists and inbox providers or accept the consequences. Those are your two choices. We recommend that you play by the rules, because they ultimately create a better inbox experience for all consumers.

So, what might a blacklist operation want you to do in order to be removed? They could ask you to:

  • Remove all email addresses that you added after a certain date
  • Send a re-permission request to all email addresses added after a certain date
  • Adopt a double opt-in subscription process across all of your subscriber acquisition sources
  • Seriously consider terminating a relationship with a partner or affiliate whose behavior directly led to the blacklisting

These remedies can be painful and distract you from running your email program, so we recommend trying to avoid being blacklisted in the first place. And we certainly recommend trying to avoid being blacklisted repeatedly.

“If a sender does not make changes to their practices, there is a big chance they will end up back on the blacklist,” says McGovern. “Then things become worse, because if a blacklist operator sees the same IPs or domains getting listed again, they can make it progressively harder to be removed. If you don’t learn from your past, you are doomed to repeat it.”

With that in mind, let’s answer the question…

What Causes Brands to Be Blacklisted?

Most blacklistings are due to high spam complaint rates and hitting spam traps. These two problems can also lead to inbox providers blocking your emails or routing them to spam folders instead of the inbox.

Spam Complaints

Having a complaint rate above 0.2% is one of many signs of deliverability problems ahead. Email recipients report emails as spam for a wide range of reasons, but some of the most common are:

  • They don’t remember signing up for emails from the brand
  • They can’t easily unsubscribe
  • The emails aren’t relevant to them anymore

Spam Traps

Hitting even one spam trap can potentially lead to a blacklisting, although typically it takes multiple spam trap hits to get you in trouble. That’s because blacklist operators, as well as inbox providers, use spam traps to detect the behavior of spammers. Spam traps come in three major varieties:

  1. Pristine spam traps. These email addresses are created explicitly to identify spammers. The blacklist operators who create these email addresses post them online in places where only the email scraping apps used by spammers will find them. So, if someone is emailing one of these addresses, the blacklist operator knows that the sender either scraped the address or bought a list containing the scraped address. Either way, the blacklist operator then lists the sender as a spammer.
  2. Recycled spam traps. When an email address is abandoned, sometimes inbox providers recycle those formerly legitimate email addresses into spam traps years later. The logic is that only spammers would email a person who stopped using that email address so long ago.
  3. Typo spam traps. Blacklist operators see it as a negative indicator of email list hygiene when brands send emails to addresses with misspelled and invalid domains like “oal.com,” “gnail.com,” “yahho.com,” and “outlok.com.” So, they use spam traps with these kinds of domains.

Together, these spam traps identify senders who are scraping email addresses, mailing long abandoned addresses, and mailing invalid domains—all of which are hallmarks of spammers.

How Can I Keep from Being Blacklisted?

To help minimize spam complaints and reduce the risk of adding a spam trap to your email list, consider taking the following actions, which we’ve labelled as either “highly recommended” or simply “recommended” depending on the impact of the action. 

Highly Recommended

Taking the following steps are critical to keeping your brand off email blacklists: 

  • Don’t link to disreputable websites. Links are the most critical pieces of content in your emails when it comes to blacklisting concerns. As mentioned above, linking to websites with poor reputations affects your email reputation and can get you blacklisted.
  • Don’t use URL shorteners in your emails. These conceal the destination of a link and are frequently used by spammers to mask URLs. Shortening even high-reputation links makes you look like a spammer.
  • Never buy email lists. You can’t buy permission, so using purchased lists automatically puts you at high risk of spam complaints. Beyond that, because for-sale email lists are often created by scraping email addresses off the internet, they tend to be full of role-based email addresses (e.g., sales@company.com), outdated and abandoned email addresses that might be recycled spam traps, and—most importantly—pristine spam traps.
  • Monitor the performance of your affiliates and partners. Terminate those relationships that result in high hard bounce rates and low open rates.
  • Use active opt-ins. Pre-checked opt-in boxes and permission grants buried inside terms and conditions are passive opt-ins that result in you adding people to your email list who often really don’t want to be there. That leads to higher spam complaints and lower engagement rates. Instead, use unchecked opt-in boxes and signup forms that are explicitly for email.
  • Avoid handwritten opt-in forms. Accuracy rates on transcribing handwritten email addresses are notoriously low, which dramatically increases hard bounce rates and increases spam complaint rates, too. Adopting digital opt-in methods are best, such as referring people to a URL for email opt-ins, having them opt-in for email via SMS, or having a tablet or kiosk present for them to use for signups.   
  • Avoid verbal-only email address collection methods. Verbal transcription accuracy rates aren’t much better than those for handwritten transcription. If verbal collection is taking place in a store, at an event, or another in-person venue, using a screen to show a would-be subscriber the email address that you verbally transcribed can boost capture accuracy significantly. However, if verbal collection is happening remotely via a call center, for instance, then using double opt-in confirmation is the safest option.
  • Suppress chronically inactive subscribers. If a subscriber hasn’t engaged in a long time—and especially if you’ve tried and failed to reengage them—then eventually it’s best to suppress emails to them. It’s generally best to send them a re-permission email first asking them to click a link in order to reconfirm their permission. If they don’t click it, you should suppress them from future emails.


Taking the following steps can also help keep your brand off email blacklists, although they have less of an impact in our experience: 

  • Use double-entry address confirmation. Sometimes people mistype their email address, but it’s very rare for them to mistype it twice in a row. That’s the logic behind asking subscribers to enter their email address and then to confirm it by entering it again in a separate field. It’s a simple and very cheap way of reducing hard bounces caused by entry errors.
  • Use double opt-in confirmation. This is the gold standard of email permission. By requiring new subscribers to confirm their permission by clicking a link in an opt-in confirmation request email, you can be 100% confident that the email address owner was (1) the person who entered their address in the signup form and (2) that they indeed want your marketing emails. In addition to decreasing spam complaints and increasing engagement rates, double opt-in guarantees that you don’t add spam traps to your email list.
  • Utilize an email address verification service. These services can help catch poorly formatted and incomplete email addresses, so they help reduce hard bounces. They can also catch some domain typos that might be typo spam traps, as well as some known spam traps that are now inactive. But email address verification services don’t help keep pristine and recycled spam traps off your list.
  • Make unsubscribing simple. When subscribers have to jump through too many hoops to opt-out or can’t easily find the unsubscribe link, they turn the never-fail “report spam” button. Don’t frustrate your subscribers and force their hand. Make the unsubscribe link easy to find and your unsubscribe page easy to navigate. 

Some of those recommendations are harder to implement than others, and some definitely have one-time or ongoing costs associated with them. Think of these costs as insurance against being blacklisted. Even in the best of circumstances, being blacklisted can be costly in terms of lost email marketing revenue. In the worst cases, it can be extremely costly, as some retailers discovered during the 2012 holiday season. 

“Spamhaus listed many large retail senders around the holidays, who had most of their mail blocked as a result of the listing,” says Moore. “Those retailers lost hundreds of thousands—if not millions—of dollars in revenue. Poor list hygiene eventually has a cost. Minimize this cost by actively and intelligently managing your audience to find a way to achieve your business goals, while mitigating risks.”


Need help with getting off a blacklist or improving your list hygiene? Oracle Marketing Cloud Consulting has more than 500 of the leading marketing minds ready to help you to achieve more with the leading marketing cloud, including an Email Deliverability Services team.

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