Marketers / Marketing Automation

Check If Your Email Domain Is Blacklisted: Here’s What to Do About It

By Siva Devaki

When an email server is suspected of sending out spam, email service providers begin blacklisting (blocklisting) either its IP or its domain. Once an IP address or domain is blacklisted, emails originating from it will end up in the “spam” folder rather than in the recipient’s inbox. Getting an IP blacklisted (blocklisted) can be extremely damaging to email marketing, but there are ways you can avoid the blacklist database.

This guide will cover how to run an IP blacklist check, and more importantly, the blacklist-removal process to restore healthy email deliverability.

Note: the terms blacklist and blocklist are used interchangeably (also disallowlist, denylist) following an industry trend moving away from using “blacklist”.

Is Your Domain or IP Blacklisted (Blocklisted)?

If you aren’t getting the response you expected from your email campaigns, your IP address or domain could be blacklisted (blocklisted).

Domains can get blacklisted if there are too many spam complaints—or if the email appears to share the hallmarks of unsolicited promotion. ISPs may block users from accessing blacklisted websites and may prevent them from receiving an email from blacklisted domains or IP addresses.

There are a number of blacklist database sites available which store email blacklists, allowing you to search through email blacklists, add to the email blacklists, or get yourself removed from email blacklists.

Common Email Blocklists

How Can You Check if Your IP is Blacklisted?

If your email domain name IP is blacklisted, you won’t get notified. Instead, you’ll need to take action to find out. Here are a few ways you can find out:

  • Check a blacklisted site directly. Many blacklists are openly available, such as net. If you want to see whether your domain is being blocked by a specific site, you can search by that site either the IP address or domain.
  • Use a dedicated blacklist tool. You can perform a blacklist check on the MXToolbox. There are free blacklist checker tools that show you the health of the domain name of your email server. There are a number of domain and IP address blacklists so each tool may not have access to all of them—you should run an email blacklist check on more than one site.
  • Check your metrics. If your open rates have gone from 30% to 5%, for example, you know something has happened that goes beyond the content of your emails. While this isn’t definitive, it’s a good sign that something along the way is causing your emails to be dropped. This could be blacklisting, failed authentication, or other issues.
  • Send test emails. Send test emails out to a list of known email addresses and see how many of them are received and whether they end up moved to the spam folder. Test emails will show not only whether emails are being delivered but how they’re being delivered.
  • Use an email monitor. A built-in email monitor, such as the MassMailer Email Monitor, will check blacklists automatically when you send emails—providing you with the fastest, most actionable information.

How Can You Remove Yourself From a Blacklist (Blocklist)?

Obviously, if you do find yourself on the IP blacklist, you need to get yourself off the list.

To get unblacklisted, you must first ask yourself: “Why is my domain blacklisted?” and determine what happened to get you blacklisted. It could be, for example, that you’re failing SPF or DMARC authentication, and consequently, your emails appear to be suspicious.

From there, you need to go to the blacklisting site and ask them to be removed. Some offer a self-service removal tool and others require you to go through a removal process; regardless, if you haven’t already fixed your email deliverability problems, you’re likely to get blacklisted again soon after.

If you are a Salesforce CRM customer, you can monitor whether your IP address is blacklisted using the MassMailer Email Monitor. MassMailer will also help you improve your email deliverability, by generating your email deliverability score, so you can avoid getting blacklisted again.

The Author

Siva Devaki

Siva Devaki is the co-founder of MassMailer and is responsible for the overall company and the product strategy.


    June 18, 2020 6:02 pm
    Perfect solution! Domain blacklisting is one of the worst case for almost every organization, even mine domain was listed in rfc-clueless blacklist which was for domain setting complaince but I never used the Mxtoolbox to check the blacklisting. I have used multivalley rbl ( but it just gave me the DNSBL were it was listed and then pepipost's tool ( for checking the delisting steps. Ideally, ESPs help to get your email programs streamlined and few step I took to make my email more simple and sophisticated.
    August 23, 2021 4:17 am
    Hey was desperately looking for this info! Thank you
    Ellen Sheehan
    April 10, 2022 4:42 pm
    I only enquired about St.Thomas hospital Stockport as I did my nurse training there.
    December 07, 2022 6:54 pm
    Hi there, my domain is not blacklisted but it saysthre are three timeouts ... what does that mean?
    Yash Arora
    March 24, 2023 2:28 pm
    How can i check if my email domain is blocked ??

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