Email Blacklist: Meaning, Reasons and How to Avoid Being a Part of It

Where we have good, we have bad too! Where there is white, there is black too!

This runs true in the online marketing world, where email marketing is considered the king and has two sides: the inbox or the spam!

So, ever faced a situation in which your open email rate went extremely down, or a major portion of all your emails landed up in spam? That’s exactly what blacklisting is all about.

Often an e-mailer lands up in a situation where they have not done anything incorrect, but on checking the status of their IP address, they discover they have been blacklisted! Having the IP or domain added to a blacklist can seriously affect a sender’s reputation and, ultimately, the email deliverability.

Furthermore, once added to a blacklist, it’s not a simple case to be expelled. It’s essential to comprehend why you’re on a blacklist and fix the root cause of the listing so your domain or IP addresses don’t end up on the blacklist again.

Let’s get into details about what exactly an email blacklist is!

Email Blacklists are live databases that decide which email will be flagged as spam.

Each blacklist serves as a filter that decides whether you will reach your intended recipient’s inbox or end up trapped in the junk folder. Thus, email blacklisting is also commonly known as ‘Spam Trapping.’

Email blacklist stores detailed data about IP locations and Domain addresses marked suspicious and known for sending spam.

To understand this better, let’s have a look at the two email blacklist categories:

1. IP-based blacklists - An IP-based blocklist is a real-time collection of sending IPs that send spam or other types of email abuse.

2. Domain-based blacklists - A domain blocklist (DBL) is a real-time collection of sending domains that have sent spam or other types of email abuse.

Now when an email is sent, Email Service Providers (ESPs), Internet Service Providers (ISPs), and Anti-spam agencies (ASAs) refer to this list to detect and block any spam emails entering their network.

An email blacklist list is not a single centralized list on the internet. However, many anti-spam organizations are maintaining their independent DNSBL list. Some lists are free to use, while few require commercial licenses.

Based on their accessibility email blacklists are divided into three types:

1. Public blacklist –These lists are accessible to the public and can be checked by anybody from anywhere.

2. Private blacklist – These lists are set up by significant ISPs to find spam utilizing internal measures and criteria. Private Blacklists are generally utilized by major ESPs such as Gmail, Hotmail, and AOL.

3. Spam firewalls – These lists are a system of firewalls and blacklists enterprises utilize to secure their internal servers. Common examples are McAfee.

Mostly, these email blacklisting servers do an excellent job of filtering out spam emails. However, how they decide what’s spam and what’s not can sometimes get well-intended email marketers marked as spam.

Imagine putting all your time and effort into a great email campaign, but your intended audiences need to see your amazing marketing campaigns. Painful right?

This is what happens When you get flagged. Your emails never make it to their desired inboxes. Instead, your domain or IP address gets added to the blacklist stopping your emails from reaching their destinations.

Getting blacklisted severely impacts your email deliverability rate and the effectiveness of your email marketing ROI.

All ESPs follow some protection protocols against various spam complaints on their platforms. The easiest way is to block your email address when it appears on an outstanding blacklist.

Hence, it drastically increases the number of bounces and reduces your email deliverability score. Here’s how email blacklisting can affect email deliverability:

1. Emails blocked or sent to spam – ESPs and mailbox providers may block or divert your emails to recipients’ spam folders, leading to low deliverability, open rates, and reduced engagement.

2. Decreased sender reputation – Being blacklisted can damage your sender’s reputation and hence your email deliverability, making it harder to reach the inbox of your intended recipients even after the blacklisting issue is resolved.

3. Reduced trust and reputation – Email providers and security systems consider blacklisting to indicate potential spam or malicious activity. As a result, even if you are removed from the blacklist, your reputation may still be affected, leading to ongoing deliverability challenges.

4. Loss of business opportunities – If your emails are not reaching your target audience, it can result in missed business opportunities, decreased customer engagement, and, ultimately, loss of revenue.

You may ask yourself, yet for what reason do I get blacklisted?

Anyone can have their email addresses blacklisted. With the spam increasing daily, mail servers had to find a way to combat those. And this is how they do it.

Now, if you’re wondering: “Why is my email blacklisted by Gmail/Yahoo/Outlook?” then it can be due to the following reasons:

1. Poor email list hygiene – Your email list hygiene plays a major role in keeping you away from spam traps. If you don’t routinely clean your email lists from inactive or duplicate email addresses, you might be incidentally setting off the spam police. Having repetitive bounces can show up on a blacklist.

2. Too many spam complaints – Email providers often blacklist email addresses that send spam or emails that are immediately deleted without even being opened. Sending emails to recipients who have not opted in usually results in high complaint rates, and it is also illegal in many countries to send emails without their consent.

3. Sending to unengaged recipients – Continuously sending emails to recipients who do not engage with your content can negatively impact your sender’s reputation and lead to email blacklisting.

4. Too many outbound emails – If you normally send out 1000 emails in a week and suddenly send out 10,000 emails daily, this will set off an alert demonstrating potential spam movement. Your service provider will likely suspect you’re up to no good, blocking your email address from sending further emails.

5. Poor email content – Emails with excessive use of spam-triggering words, poor formatting, or misleading subject lines can be flagged as spam and lead to email blacklisting.

6. Virus/ Malware – Your PC might be infected or infected. You may not know about this, but it will influence your active mail and make you appear on spam blacklists.

7. Email spoofing – Creating a message with a fake sender address is easy. Hackers might make it appear that the messages are coming from you, causing harm to your reputation. This will make you look suspicious and get flagged as spam.

8. Hacked or compromised email account – Hacking is the most common reason legitimate email users are blacklisted. If your email account is compromised and used for spamming, it can result in blacklisting.

Keeping an on the KPIs of your email campaigns will help you figure this out. 3 common indicators that tell if your email has been blacklisted are:

1. More emails getting dropped- When your recipient reports your email as spam or unsubscribes from your newsletter.

2. Falling deliverability rate- When you fail to reach the recipients’ inboxes, you will notice deteriorating email deliverability.

3. High email bounce rate- When your messages can’t be delivered to the email addresses on your list and end up being bounced back to you.

However, these are not enough to confirm whether you are blacklisted. If you see a drastic fall in email deliverability, it’s better to check for your domain or IP address on the email blacklists.

If you’re facing any of the above signs and are worried that your email address has made its way onto the dark side, your best bet is to sign up for blacklist checker tools. These tools help you look up your name in the email blacklist servers.

Some of the most common email blacklisting databases to look for your IP or domain name in are:

You can use tools such as MXToolbox’s Blacklist Check, Spamhaus IP Blocklist Checker, Barracuda IP Blacklist/Blocklist Checker tool, and so on…

Once you have fixed the issues, go to the blacklist site and follow their IP address removal instructions. There are blacklists with a self-removal service and a time-based removal service.

1. Self-removal –It lets you take your IP address off the blacklist without much trouble, but you need to remember that if the address gets listed again, it won’t be easy to remove it the next time.

2. Time-based removal –A built-in, automatic process removes lower-level listings (IP addresses that are light offenders) within a week or two. But the period would be longer if the IP address had sent spam more than once or at a high volume.

One needs to follow the rules and cooperate with the instructions and terms and conditions provided. Honesty and open statements play an important role in resolving the blacklist issues. If not, and the blacklisting is troublesome for you, consider contacting the list maintainer by phone and trying to resolve the issue that way.

👉 Read: Email Blacklist Removal: Guide To Remove Email From Blacklists

Prevention is better than cure. Once you get yourself on the email blacklist, it can take time to recover. Hence, it is best to practice good email habits to stay away from blacklist territory.

Here are 6 ways that will help you stay off the email blacklists:

Purchased lists are loaded with unpalatable things, much like a nutty delight. We’re talking about invalid addresses, spam traps scratched from some sites, and old addresses that may now be spam traps.

Also, recipients on these lists have yet to opt to receive your email messages, which thus will create higher complaint rates. High complaint rates feed into various blacklists that track user spam and abuse complaints, so avoiding any bought list is ideal.

Rather than buying such lists, focus on building a quality email list.

Giving subscribers a clear option to unsubscribe from emails is very important.

If they do not wish to receive your emails anymore, it’s better to let them unsubscribe rather than marking you as spam which will cause far more damage to your business. Also, providing an unsubscribe option improves customer experience and enhances your brand’s image.

Maintaining a clean email list is very important to keep yourself off email blacklists.

Always use email validation tools to check the legitimacy of your email list and update them regularly. Subscribers who haven’t engaged with you for at least six months should get re-engagement emails. And if they still remain unresponsive, you should remove them from your email list.

Also, check for invalid, inactive, and temporary email addresses before sending out your email campaigns. Here’s how you can use Clearout to bulk validate the email addresses in your list and maintain better email hygiene.

Personalize your emails to the greatest extent feasible, and avoid sending generic emails. This will greatly reduce spam complaints.

If you provide valuable content to your subscribers, they will not mark your email as spam. So, avoid being too promotional or using spam trigger words and focus on providing quality content to your readers.

When an email address or domain gets blacklisted, the emails sent from that address or domain are often automatically routed to recipients’ spam or junk folders, significantly reducing the chances of the emails being seen or read.

To ensure that your email campaigns or communications reach your subscribers’ inboxes and avoid being flagged as spam, it is helpful to ask your subscribers to move your email to their inboxes. This practice is known as “whitelisting” or “adding to the safe sender list.”

This is a two-step verification process. The user needs to confirm that they signed up to receive emails from you, i.e., they need to confirm their subscription.

This method ensures that all of your subscribers are real individuals who want to receive your emails- new offerings, promotional offers, or newsletters.

Thus, the double opt-in method reduces complaints about email spamming and lowers the number of opt-outs.

Put proper security measures in place. Make sure to use IP-checking tools that can protect your server from malware or bots. You don’t want to be the victim of an email hijacking.

Failure to do so can get you blacklisted, no matter how strictly you follow the best email marketing practices.

You can use an IP email blacklist lookup tool to determine if anyone uses your IP address. If the results say it is being used by another server, your network server was hacked.

Also, make sure that your emails are authenticated to ensure the legitimacy of domains and avoid getting blacklisted.