The Dreaded Email Blacklist: What to Know, How to Avoid It, and Why We Need It

Melanie Balke
October 24, 2022

Few things are as fearsome as the dreaded email blacklist. This near-monolithic enemy is always looming, searching for errant email marketing to toss in the junk folder. It’s the Big Bad of email marketing, but it doesn’t have to be that way!

In fact, spam filters are protectors, and avoiding blacklists will improve your marketing.

Today, I’ll be shining a light on the darkness of email blacklists.

What are they? How does one end up on an email blacklist? What can be done to avoid spam words and complaints?

Keep scrolling to learn more about the email blacklist and how your company can avoid its grasp.

What Is an Email Blacklist?

At its core, a blacklist database is what it says on the box: a list.

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Spam filters are maintained by a mix of public efforts, private enterprises, and internet service providers. However, these lists are useless without a platform! To work, blacklists must be added to an email service provider’s software. Some blacklists are free, some are native to an email service provider, and others are purchased from private companies.

Most major email service providers use a mix of their own internal blacklists and third-party blacklists.

However, all blacklists — regardless of their source or maintenance — work the same way.

Think of email blacklists as the virtual equivalent of a sorting center. When a user receives an email, the message passes through the ESP’s spam filters, which compare the message’s information to the server’s preferred blacklist database. If a trigger is tripped, the message will be funneled into the user’s spam folder or deleted entirely.

There are two types of email blacklists.

The Domain Blacklist

A common way to filter spam is a domain-based blacklist. These filters target senders’ domain names and URLs.

Most email service providers use URI Real-Time Blacklists (URI DNSBLs), which enable real-time tracking and deletion of spam messages.

Beyond the most basic filtering, which will only check the sender’s immediate URL, advanced filters will search the sender’s site to find any possible redirects. If a page redirects to a known spam domain, its sender will be considered a spammer.

IP-Based Blacklists

One of the most reliable methods used to avoid spam is an IP-based blacklist. These databases list known spammers' internet protocol addresses (known as the “IP address”). The technical term for an IP blacklist is a Domain-Name Server Black List (DNSBL).

When an email from one of the listed server IP addresses enters an inbox, an IP blacklist automatically deletes it.

How to Dodge the Spam Folder and Avoid Blacklists

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Nobody wants to land in the spam folder, and businesses need their email subscribers to receive their messages. Being branded as spam will hurt your brand reputation and damage your ability to deliver content to your email list.

Fortunately, there are plenty of ways to avoid the spam folder!

Avoid Purchased Lists

Purchased lists are the fastest way to malign your email marketing efforts and destroy your email delivery chances. While these databases may be tempting, the results will always be subpar.

A header image features a photo of leaves. The text reads, “Spam Traps: The email marketer’s worst nightmare can be avoided entirely!”

The best possible result is that you’ll receive a contact list full of uninterested consumers.

However, it’s far more likely that you’ll end up with a bunch of useless contacts and spam traps. Anti-spam vendors use these false addresses as honeypots to attract, identify, and flag nefarious spammers. The most common spam traps are:

  • Dead Address Traps are common consequences of poor list hygiene. A dead address trap uses abandoned or deactivated accounts.
  • Investigative Spam Traps are the least worrisome. These preemptive addresses are manually entered into email lists to monitor a sender’s activity.
  • Pristine Traps are purpose-built email accounts that can only be obtained by scraping website code.
  • Pure Traps are planted addresses, which work like pristine traps.
  • Recycled Spam Traps are dormant email accounts that are commandeered as easy-to-miss spam traps.
  • Typo Traps use slightly misspelled email addresses and are most commonly encountered when marketers fail to verify emails properly.

Aside from an investigative spam trap, all of these spam trap addresses will harm your sender reputation. Some of the more serious offenses (i.e., pristine and pure traps) may even damage your domain reputation and impact your IP addresses.

Practice Proper Email List Hygiene

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Keen readers may have noticed that some spam traps aren’t actually related to purchasing a contact list. In fact, some of the sneakiest traps are the result of poor list hygiene!

As marketers, it’s our duty to watch our stats. Bounce rates, engagements, and email deliverability are all part of the process, and improving these metrics will decrease your chances of landing on a blacklist and boost your success!

Marketers should strive to clean their lists yearly at the least.

If you’re maintaining your list manually, this can be a lengthy process. However, marketing automation makes things a lot simpler. With a bit of basic coding, marketers can set their own rules for engagements, bounced email addresses, and re-engagement. Many email marketing platforms will also remove inactive addresses automatically.

The most important things to look out for when you’re cleaning your email list are:

  • Bounced emails
  • Email deliverability
  • Engagement rates
  • Spam reports

Avoid Spam Words and Deceptive Subject Lines

A header image features a photo of computer circuitry. The text reads, “Spam Words: Balance their usage with engaging content and proper practices.”

It may seem obvious, but it’s still worth saying: Never use clickbait in your subject line. This tactic might draw more clicks, but it never leads to actual engagement. In fact, deceptive subject lines are a great way to have your email blacklisted after users inundate you with spam complaints!

There are plenty of free email tools to check your messages for spam words.

However, — as a disclaimer — you don’t need to avoid spam words entirely. There are situations where you’ll have to use these common trigger phrases for clarity, and that’s okay!

The important thing to remember is that your sender reputation will influence your email delivery; if you keep your nose clean, you’ll have little to worry about when it comes to spam complaints.

Warm Up Before You Send Out

Whenever you’re sending a marketing email, you’re using your mail server, and that mail server’s IP address is linked to an internet service provider. What I’m saying is that your email server has a vested interest in maintaining its own integrity, so complying with their guidelines is a mutually beneficial act.

Part of this two-way relationship is maintaining steady email volumes. Your brand has certain email campaign stats, and going wild can harm both your brand reputation and your mail server IP address.

All of this is to say that you need to warm up your email account before you start sending more emails. If you suddenly send thousands of messages when you usually send a few hundred, most servers will assume that these are spam emails. This reduces the likelihood that your email marketing will land in your recipient’s inbox and harms your relationship with your ESP.

An infographic with a photo of leaves. The header reads, “Warming Up: How to Warm Up Your Email Marketing Address.” Smaller text reads, “When you’re sending emails, large spikes in activity can signal to providers that you may be trying to send spam. To avoid this incorrect assumption, you’ll want to ‘warm up’ your email account. This can be done by slowly increasing the number of emails that you dispatch each day.”

If you’re planning to send a big campaign, notify your email providers! Aside from being a kind courtesy, this advance warning can help the server allocate more resources for your brand’s marketing.

Make Sure Your Email Marketing Efforts Comply With Legal Requirements

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Finally, you’ll want to ensure that your email marketing complies with all relevant legislation. Subscribers should only be emailed after submitting a proper opt-in form, and recipients should be able to quickly and easily opt out of your marketing emails. Some companies go the extra mile by adding a double opt-in form to their website.

Ultimately, most companies on a blacklist are there because they failed to comply with clear guidelines.

The best way to keep your server IP or domain name clean is to ensure you’re only sending emails to a receptive audience.

How Do I Know If My Brand Is on an Email Blacklist?

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If you’re worried about the status of your IP address, there are a few ways to check it. More importantly, there are ways to remove your IP address from every major spam list.

That being said, the best way to remove your email domain from a spam list is to avoid it altogether!

Blacklist Check Tools and Tricks

The first step to making sure you’re sending emails that reach your customers is knowing your status. Most major email services have tools to avoid blacklists and check your status.

However, there are also resources dedicated exclusively to blacklist checks. All of the major spam lists have their own list-checking tool, including Spamhaus; most of them will also tell you how to remove yourself from their blacklist.

How to Escape the Email Blacklist

If you find that your address is on a spam list, don’t panic! Follow the instructions on the website to have your server IP or domain removed from the blacklist.

Usually, you’ll have to submit some documentation to have your IP address removed from a blacklist. At the bare minimum, spam lists will want to see that you’ve addressed the root cause of your spam complaints.

For example, you may need to reinforce your internal security if your account has been hijacked by a botnet. Alternatively, your signature may need to have a return address added to comply with local anti-spam regulations.

Call in the Professionals!

If all of that is a bit much, that’s okay!

A header image features text overlaid on a photo of a padlock. “Blacklists: The Advantages of Professional Info.”

There’s enough to worry about when you’re crafting email campaigns, and a blacklist check is just another cog in an astoundingly complex machine. Working with email blacklists is hard! It’s a tedious balancing act of conveying your message without appearing too spammy.

That’s why many companies turn to professional email marketing agencies.

An agency — like The Email Marketers — is staffed with marketing experts who know how to avoid the dreaded blacklist and maximize your marketing automation. An agency can grow and nurture your email list and amplify the impact of the humble email address.

If you’re ready to see the difference an agency can make, let me know! We can discuss your marketing plans and come up with a strategy that fits your brand.

In the meantime, check out the rest of my blog. I’m always updating it with more tips, hints, and tricks to amplify your email marketing!