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What Is An Email Blacklist?

  • Mar 03, 2022
  • 0
  • by Kate Meda

Have you ever emailed someone and didn’t receive a response? You may have wondered why your email went unanswered. The recipient may have simply been busy or didn’t see your email, but it’s also possible that the recipient’s email server blocked your email. One way an email server can block emails is by using a blacklist. This blog post will explain what an email blacklist is and how to avoid being blacklisted yourself.

What is an Email Blacklist? 

The email blacklist is an extensive database of public domains and IP addresses marked as suspicious for sending spam emails through the internet. It’s also known as DNSBL (Domain Name System-based Blackhole List) or RBL Real-time Blackhole List. Organizations like Email Service Providers (ESP), Internet Service Providers (ISP), and anti-spam agencies (ASA) use this list to detect, monitor and block any spam emails entering their network. 

Am I Blacklisted? What Are the Signs?

There are many signs to alert you of your IP’s status. When you’re blacklisted, you can’t send emails to the recipient’s mailbox properly. Now, this doesn’t mean you’re going to be blacklisted from every mail server in the world. If you’re blacklisted with one DNSBL service, there are hundreds more that may not have blacklisted you. A few key signs:

  1. There are an increased number of emails lost. 
  2. You experience deteriorating delivery rates.
  3. You find a high number of email bounce rates. 


These don’t confirm you’re blacklisted but are some warning signs. If you check a few of the boxes for delivery issues, you can now check to confirm the blacklisting of the domain or IP address. 

Checking Your IP address and Domain in an Email Blacklist Directory

There are various email blacklist services on the internet. It’s not practical to check every single one of them, but some applications maintain a list of live RBL (real-time blackhole list) directories to save your time. They provide a page dedicated to that RBL service and also offer a service to delist your domain or IP address. 

Here are a couple of popular RBL applications:

  • MXToolBox: This checks for domain blacklisting across multiple RBL lists. It provides detailed information and suggestions on your domain’s current status. 
  • MultiRBL: This is a free DNSBL lookup site that can scan 100+ DNSBL lists to check for domain blacklisting. It also details the steps to remove your domain from the blacklist. 


Malicious sites can be blacklisted by Google Safe Browsing, which will warn visitors of potentially unsafe pages. Dropmysite includes a feature that sends you alerts if your site is listed on this blacklist monitoring program – so take immediate corrective actions before it gets too late! A2 Hosting offers Dropmysite as an add-on cPanel plugin so that you can back up your data and monitor your websites. These services can help you actively monitor your IP address so that you can ensure swift delivery of all of your emails. 

Blacklists are an important tool for email deliverability. They help protect email users from spam and phishing emails and improve the deliverability of your legitimate email campaigns. If you’re not familiar with blacklists or aren’t sure if your IP address is on one, we encourage you to use a blacklist checking tool. Use this information to clean up your email practices and improve your chances of getting delivered to the inbox. If you have any more questions or concerns feel free to contact our support team 24/7/365!

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