Email Blacklists: How To Check And Avoid Them

Email blacklists are the biggest fear of an email marketer.

Every marketing professional is always looking forward to ensuring maximum email deliverability rates when they use email marketing campaigns to increase sales. 

However, sometimes things don’t go as planned. You can find that your IP and domain is blocked from sending emails to almost every subscriber on your mail list. 

You feel off the hook, and believe there is nothing you can do to revive your marketing campaign.

Most marketing experts will tell you that they have once been on a blacklist, but they never stopped there. There is always a way out for you. 

In this article, we explain the meaning of an email blacklist, how blacklists function and give you some tips on how you can avoid blacklisting your email address in the first place.

What is an Email Blacklist?

An email blacklist is simply a long list of domains or IP addresses that have been reported or known to send spam. In most cases, free mailbox providers, ISPs, and anti-spam vendors use email blacklists to safeguard their systems from getting spammed. 

Because Internet Service Providers (ISPs) and anti-spam vendors have their specific blacklists, you are likely to find your domain name or IP in more than one blacklist as long as you are frequent in sending large amounts of emails.

Did you know that at least 85% of emails that are sent daily are considered spam? Well, that sounds annoying, considering that most email marketers would spend a lot of time and resources to craft a quality marketing emails only for them to land on the spam folder. 

Also, it is recommended to send your emails using a reputed email service provider.

Related: Best Email Marketing Services

Blacklists help keep large amounts of emails from people’s email inboxes. Every ISP has an internal email blacklist that stops unwanted messages from entering their customers’ email inbox. 

Types of Email Blacklists 

Several identification algorithms determine whether an email is abusive or contains spamming content. Every ISP has its specific policy to determine whether an IP or domain should be blacklisted. 

When an email address is blacklisted, it cannot deliver any emails to anyone. The emails sent by a blacklisted IP address will not land on the primary inbox of any recipients.

The different types of email blacklists are:

• Domain blacklist: this is a real-time list of all domains that are sending misleading messages and spams to people.
• IP address blacklist: It is a list of all IP addresses that ISPs and anti-spam vendors suspect to be sending abusive or spam content to people.
• Spamhaus Block List (SBL): This is a blacklist for all email addresses that are not owned by real people. Once you have your email address on this blacklist, you must follow the right protocols to remove it here. You can contact the Spamhaus Blacklist Removal Center for further action.
• Composite Blocking List (CBL): Your email address and IP address are likely to appear on this blacklist if it shows malicious behavior like dictionary attacks, open proxies, and spambots. In most cases, hackers will run an open proxy or dictionary once they hack a website. If that happens, your IP address will be included in the CBL. Fortunately, you can request the removal of your IP on the CBL.
• Barracuda: if there is any breach in your website security, then your IP will appear on this blacklist. You will find your IP address listed on Barracuda Central. To remove your IP address from the blacklist, you simply fill an online request form for removal and wait for the next 24 hours before you can start sending emails again.
• Spamcop: Most IP addresses find their way on this blacklist because of security issues on sites. Spamcop uses spam reports and spam traps to determine whether it should blacklist an IP address or not. Once you manage to bring down the spam source in your site, Spamcop will remove your IP address from the blacklist.
• XBL Exploits Block List: All hijacked IP addresses are listed on the XBL. This blacklist includes all IP addresses of servers that have been used as a spam gateway. To remove your IP address form the XBL, you can contact the Spamhaus Blocklist Removal Center.

How Your IP Address or Domain Gets Blacklisted 

Below is an illustration from Spamhaus, an operator or the biggest blacklist, showing the email blacklisting process.

This is how the blacklisting process works. You send an email (Sender ), and your ISP (Receiver) receives it. The company goes through the email and finds out if the IP address of the email sender is listed on the Spamhaus data. 

The ISP checks their spam filters to find out if there is anything in the email that they do not allow. If the email is found to have no spam or malicious content, the ISP decides to send the message to the recipient’s primary inbox. 

An email blacklist is just one of the tools that ISPs will use to determine if an email is legitimate. Every ISP has a unique policy that it uses to establish the legitimacy of an email. 

If an email is rejected, then it has probably not passed the ISPs policy. In the above diagram, the ISP has rejected the sender’s email based on the Spamhaus data and company policy.

How Your Emails Get On Email Blacklists 

It doesn’t take much for your email address or IP to appear on any blacklist. It may look technical somehow, but as long as your ISP company is going to receive many spam complaints from users, they will automatically block your email address from sending any marketing content to people. 

Below are some three ways your emails can get blacklisted:

• Lots of bounced email addresses: You have a lot of bounced email addresses on your mail list. Your ISP is likely to blacklist your domain or email address if you are having a bad list or lots of bouncing email addresses. Most people that purchase lists from third-party marketing sites are more likely to fall into this trap. Purchased email lists may have a spam-trap email (an email that is not used by anyone). Blacklists use spam-trap emails to find out bad lists and email addresses that send spam content.
• Suspicious email lists: ISPs have set algorithms that can easily predict suspicious email lists. A normal email list should grow over time as new customers subscribe to the list to receive emails. A sudden surge in the email marketing list is an indication that you have purchased a new email list from a third party. 
• Spam complaints from users: when most of your email list subscribers hit on the spam button, your ISP will get a notification that your email address could be sending spam content to users. If the ISP receives many complaints from users, it is more likely to block your email address from sending emails. This happens to almost every email address that sends many emails daily. 

How Do You Know If Your Emails Are Blacklisted?

Nobody would like their email address or IPs to appear on any ISP blacklist. It is always vital to avoid being in the dark, especially if you notice anything fishy with your email marketing campaign.

In some rare cases, your ISP will notify you if your email address or domain has been blacklisted. To be certain, you can always carry out some manual checking and find out if your email address is blacklisted.

Here is how you can find out if your email is blacklisted:

A Sudden Fall In Your Email Open Rate

Email open rate is an important metric in email marketing. When you notice a significant decrease in the number of people opening your emails, then it could mean that your email address is blacklisted, and most of your emails are not being delivered to your recipients’ mailbox.

Run A Test

You can always use tools such as Isnotspam, Mail-Tester, and Glockapps to find out if your email address has any issues. These tools are very easy to use. You only have to visit their sites and send an email to their email address. Once they receive an email, they will run a test on your email address and give you a report of any spam. The report highlights all the changes that you should make on your email address to remove it from an email blacklist. 

Check With Public Blacklists

The first thing you should do if you realize a low deliverability rate for your emails is checking if your email address or IP is appearing in any public blacklists. Use your domain name to find out if you have been blacklisted. 

You can visit sites such as Spamcop, Spamhaus, SURBL, and MXToolBox to find out if your IP address or domain name has been blacklisted for sending malicious content.

Once you find out that your email address is listed on any of the public blacklists, you can simply file a removal request. 

Most sites will have your email address removed from their blacklists in less than a day if you have removed any security issues on your website. 

8 Ways to Avoid Email Blacklists 

Here are the ways to avoid email blacklists:

Audit Your Email List Regularly 

If you have a large mail list, then you should audit it regularly to find out if it has any unengaged contacts. 

It is promising to have a hefty email list, but if most of the contacts on the list are inactive, then you should always be on the watch because it doesn’t do you any good but expose you to public blacklists.

Related: Email Finder – Hunter.io

Keep an eye on any inactive email addresses on your mail list because they may have been converted into recycled spam-trap by ISPs.

The rule of the thumb here is that you should remove from your mail list any email address that has not opened your emails in a year. 

There is a higher possibility that the email has been recycled to a spam-trap, and sending messages to this email will only increase your chances of appearing on a blacklist.

Do Not Add Email Addresses On Your Mail List Manually 

There is another one-way ticket to getting blacklisted that you should refrain from. That is manually plugging contacts from your business prospects and including them on your mail list. 

In most cases, if someone does not subscribe to your email list, they are not likely to welcome any marketing emails from you. 

Therefore, to reduce the number of users reporting you to ISPs for sending them spam content, you should only send emails to those who’ve subscribed to your email list willingly. 

Related: Free Email Marketing Tools

If you include your prospects on your email marketing program without their consent, they are likely to flag your emails as spam, which increases the possibility of being blacklisted.

Confirm That All Email Addresses On Your Mail List Are Valid 

Most users make typos when entering their emails. If you have an email program that requires people to enter their email address manually, then you should expect them to make some typos. 

Therefore, you should always confirm that every email on your email list is valid. 

Mailbox providers will bounce any emails that you send to an invalid email address. Also, having lots of invalid emails on your email list lowers your deliverability rate and heightens your possibility of getting blacklisted. 

You can use email address verification tools like Zero Bounce and Kickbox to verify all emails on your mail lists.

Don’t Collect Emails Addresses Organically 

If you are hungry for fattening your mail list, you may be tempted to sort emails organically from old and expired websites. The truth is that most ISPs have already set spam-trap emails on such sites, and picking any emails from the sites makes you more susceptible to being blacklisted. 

Do not collect emails organically from third party sites or send marketing messages to any emails that have not registered to your email program. 

You reduce the risk of appearing on email blacklists by keeping your mail list clean and only communicating with those who have joined your email program.

Send Custom or Personalized Emails 

Today, almost every company is sending their prospects direct emails TO inform them of the latest deals. 

Subscribers’ inbox is flooded with random marketing emails that they look forward to blocking or reporting as spam to their ISPs. 

If you want to reduce the risk of your emails being marked as spam, then you should start sending personalized emails to every contact on your mail list. 

By sending personalized emails, you are not reducing the risk of being blacklisted but also increasing your open rate. 

Always send emails that are in line with the customers’ shopping journey and target delivering them value. Most people are likely to hit the spam button if your emails are feeding them irrelevant content. 

Write Relevant Subject Lines

When crafting your email subject lines, you should make them relevant to your audience. 

It should be able to capture the recipients’ attention and show what the emails are all about even before they can open it. You improve your open rate by having relevant email subject lines.  

It could be tempting to write the “Re:” on your email. However, you should always avoid it because it increases the possibility of your email subscribers marking your emails as spam. Come up with a clear and well-researched subject line on your emails to increase the open rate. 

Include The Unsubscribe Link On Your Emails

Hiding the unsubscribe link on your emails is one way of showing people that your emails should go to their spam folder. 

Every email must have an unsubscribe link below them according to the anti-spam laws. Hiding or removing the unsubscribe link on your email is sending a signal to blacklists. 

Spam filters can easily spot your email and IP address if you don’t have the unsubscribe link on your emails. 

Also, you must remove any contact from your database if they unsubscribe from your email list. The trick is that you should keep updating your mail list and ensure you only send emails to those who are willing to interact with your brand.

Have The Best Email Design 

Don’t make your emails more attractive with bold and flashy colors. Instead, include a call to action with mild colors that may not look to enticing to the reader. Flashy emails are most likely to end up in spam filters. 

Before you embark on having the best email design, you should major in building a brand for your business and establishing a credible and trustworthy online image.

By doing this, your subscribers will be more willing to open your emails.

How To Get Off An Email Blacklist

There are several types of blacklists that your email address and domain name could appear. If you notice a sudden decrease in your email open rate and deliverability, the first thing to do is to confirm if you are listed on those blacklists.

Each blacklist has a unique unlisting process that you must follow. In most cases, if you visit the blacklist site, you will have to prove that you are not a robot before you can proceed to file an email blacklist removal request. Also, before you can proceed to contact the blacklisting site, you must ensure that you have identified and removed the issues that led you into being blacklisted in the first place.

When sending your blacklist removal request to blacklist owners, you will have to fill out an online form or send them an email explaining the situation. 

Apart from contacting a blacklisting company to remove your email or IP address from their blacklist, you can simply act on the issues in your email program. 

Note that some blacklists do not have a blacklist removal process. They only remove your IP address or domain from their blacklists over time if they realize that you have stopped any activities that that are suspicious. 

In some cases, it could be your email service provider’s duty to remove your email address from a blacklist. 

The email service provider can cancel your subscription if you are using a shared IP address that is sending spam content. You must always ensure you are employing the best email marketing practices to avoid cancelation of your email address by email service providers. 

Follow these ways to get your email address or IP delisted by blacklists. 

Permission Pass Campaigns

Your email service provider will normally identify a campaign that led to your email or IP address being blacklisted. You can easily go to your mail list and track an email that your ISP used as a spam-trap to blacklist your email address.

If you manage to track the mail list, you can send all the contacts a one-off re-engagement email to find out any emails on the list that has been inactive or have not interacted with you for the longest time. 

Any inactive contact on your list could be the one that triggered the blacklist. Remove all contacts that do not engage with your permission pass campaign to reduce the risk of being blacklisted again.

Enter A Spam Rehab Program 

The best way to keep off email blacklists is to work closely with blacklist operators. You should employ email program best practices that will prove to the blacklist operators that you are a reliable and trustworthy email sender. 

Stick to the best email campaign practices for a certain period to build trust with the blacklist operators.

Final Thoughts 

If you are using email marketing to increase your customer acquisition rate, then you must ensure you observe the best email practices. 

Your email address can easily get on multiple blacklists if you don’t send emails to the right people. 

Always monitor the statistics from every email campaign that you send. It helps you determine if those on your mail list like your content or not.

Clean up your mail lists and track the kind of content you send your contacts. 

If you land on a blacklist, you should first work on removing all the security issues that led you there before your contact your ISP or the blacklist operator. 

Lastly, use the hacks we have listed here to keep your email address from appearing on an email blacklist.