What are email blacklists?

July 7, 2014

An Introduction to Email Blacklists


What are email blacklists?

What Are Email Blacklists?

Receiving networks often use third party blacklists to reject and filter email. These lists are public databases that use various criteria to catch and identify spam. Being listed can dramatically alter or, even worse, prevent the ability of senders to successfully deliver email to their intended recipients.

What are the most common email blacklists?

One of the largest and most well known blacklists is Spamhaus. Currently Spamhaus acts as a nonprofit filtering email to over 1.9 billion email recipients. There main purpose is to identify and pursue spam and malware gangs worldwide, and sometimes work with law enforcement to bring them to justice. You can find more details and deeper look into the world of a blacklist creator at spamhaus.org.

Other popular email blacklists are:

What happens if my IP or domain gets blacklisted?

If your organization finds itself on a blacklist fairly or unfairly, there are steps you can take to correct the issue. The bad news is that without proper monitoring and a change to your emailing practices, you are likely to continue showing up on the same blacklists.

Here are some options for getting your IPs or domains removed from email blacklists:

Resolve the issues that lead to the blacklisting

The first step in resolving a blacklist issue is to determine why you were blacklisted and identify your problematic sending habits. There are a number of reasons why your IPs or domains could have been flagged and the some common issues are misconfigured networks or mail servers. You should start by validating DNS records, enforcing stronger passwords, and confirming that your servers are updated, patched, and virus-free.

Blacklist Removal

There are two common methods to blacklist removal: self-service and time-based removal. Luckily, some blacklists have a self-removal option available for you to make your case. If not, most blacklists will automatically remove you after a week or two depending on the severity of the offense. If you choose to contact a blacklist directly to request removal, always be polite and patient with them to improve your chances of a speedy removal.

Blacklists can be avoided by following some basic email best practices. We’ve put together a short list of best practices for successful emailing if you want to learn more.

Author: Alex Griffis

Alex Griffis is the VP of Product (a product geek) at 250ok, where he focuses on product design and improving our customer experiences.

You may also like...

The Year in Email 2019

It’s hard to believe we are nearing the end of yet another exciting year in email, and 2019 proved to be one of the most momentous and active years to date. Over the past year, the number of new technologies, mergers and acquisitions, mailbox provider (MBP) announcements, news, and highlights is evidence of the versatility […]

[Infographic] Global Privacy Relationship Status: It’s Complicated

I recently gave a presentation on global privacy regulations to a post-graduate marketing class and one of the things I noticed while preparing was that even within a single country, privacy is complicated. On a global scale, it is really complicated. For example, Canada has one federal private sector privacy law, three similar provincial laws, […]

The Year in Email 2018

*Update: This article was featured on email influencer Jordie van Rijn’s emailmonday blog! To see it in action, plus a great round-up of other articles and thought leadership looking forward to the future of email, click here.* The Black Friday emails are deleted, marketers’ email lists are checked twice, we pretty much know which senders […]

Ready to get started?