What is a blacklisted domain? How can it be corrected?

Learn about blacklisted domains. Find the best ways to correct it through our comprehensive guide.

What is a blacklisted domain?


The email domains are blacklisted due to several reasons. This makes it impossible to use that domain for sending or receiving emails. Some of the reasons why the domains are blacklisted are:-


  • Too many spam complaints
  • Use of abusive email content
  • Retargeting those audiences who once unsubscribed

Due to the above-mentioned reasons, the domains are blacklisted by internet service providers (ISPs). As a result, the emails enter into the spam box or get blocked by the ISP more often. 


What are the types of blacklisted domains?


The blacklisted domains can be of the following two types:-



ISP blacklisting


  • For each and every ISP there are a set of spam filtering rules or algorithms. These detect domain reputation and 80% of these are based on user engagements.
  • ISP allows the users to report spam complaints about the received emails.
  • In such a case, if a user marks the email as spam. Then, the overall impact on the email sender is very high.
  • For measuring the domain reputation there are a set of metrics which includes lower open rate and click rates.
  • Other than these the remaining 20% of cases evolve from the sending infrastructures like authentication types (SPF, DMARC, DKIM) and IP.


DNSBL blacklisting


The Domain Name System Blacklist (DNSBL) contains lists like:-
  • Composite Blocking List (CBL)
  • Spamhaus Block List (SBL)
  • XBL Exploits Block List
  • Spamcop
  • Passive Spam Block List (PSBL)
  • Invaluement
  • Barracuda
  • SenderScore

This list is used by the ISPs for checking the domain's reputation. In case the domain is found listed then it is blocked.


How to correct the blacklisted domain?



You can correct the blacklisted domain in the following manner:-


  • You should target only the active users and focus on improving the open and click rates.
  • You should not retarget the unsubscribed users or the ones who reported a complaint against your emails. 
  • The majority of the DNSBLs provide an option to contact them and get your domain removed from the list. You need to check this option and take an action accordingly.
  • Some of the DNSBLs keep a close check on the domain activities and automatically remove them from the domain blacklists. Therefore, you can do a time to time check after following the right practices. 


Important FAQs


What is blacklist monitoring?

Blacklists are lists of IPs and domains that are believed to be sending spam to users’ inboxes. Blacklisting hurts a business's reputation and email deliverability rate. You should review your email content and identify domains that are blacklisted with our blacklist monitoring tool.

How can I find out if my domain is blacklisted?

Mailercloud’s blacklist monitoring tool helps you avoid potential blacklisting scars on your email and improves your reputation. We will be carefully checking your email header and content for blacklisted domains.

You can see the number of blacklisted domains soon after you click continue after choosing your contacts.