4 August, 2025
7 Min Read
If you’re doing cold email or running email campaigns for your business, there’s one thing you always want to avoid which is domain blacklisting.
When your domain gets blacklisted, your emails stop reaching people. Even if your message is perfect, it might end up in the spam folder or get blocked completely.
And the worst part? You might not even know it happened.
Many of our clients at Nexyel came to us after noticing a drop in open rates or replies. Most of the time, the issue was not their writing or offer instead their domain had been blacklisted.
In this blog, I’ll explain what domain blacklisting is, how you can check if it has happened to you, and what steps you can take to fix it.
I’ll also share what we do at Nexyel to protect our clients’ domains from getting into this kind of trouble.
This is especially important if you’re sending cold emails from Google Workspace or Microsoft 365. Even if your setup looks perfect, a blacklist can still ruin your efforts.
So let’s go step by step and learn how to spot the problem and solve it early.
When you send an email, it travels through different servers and spam filters before it reaches someone’s inbox. These filters look at your domain name and check if it’s on any known “blacklists”
A blacklist is a database of domains that are marked as unsafe, suspicious, or spammy. If your domain is listed there, most email systems will either block your email or send it to the spam folder.
Your domain might get blacklisted for different reasons –
It does not always mean you did something wrong on purpose. Sometimes one small mistake can lead to blacklisting.
For example, one client we worked with was using a shared cold email list they bought online. The list had many invalid addresses.
After just one week of sending, their domain got blacklisted on two major services.
So even if your email setup looks fine, always be aware that blacklisting can happen quietly. That is why it’s important to check regularly.
Now let’s talk about how you can find out if your domain is blacklisted.
The good news is, there are free tools online that let you check this easily. You just enter your domain name, and they scan multiple blacklist databases to see if your domain appears on any of them.
Here are some popular tools we use at Nexyel:
These tools check your domain against well-known blacklist providers like Spamhaus, Barracuda, SURBL, and many others.
If your domain is clean, they will show all green results. But if it’s blacklisted, you’ll see a red warning next to the name of the blacklist provider.
Make sure you also check your sending IP address, not just your domain name. Some blacklists are based on IP, especially if you’re using shared email tools.
At Nexyel, we include weekly blacklist checks as part of our domain monitoring service. This helps us act fast before a small issue becomes a big problem.
Checking your domain takes just a few minutes, but it can save your whole campaign.
If you find your domain on one or more blacklists, don’t panic. It happens to many people who run cold email campaigns.
The first step is to figure out why it happened.
Go back and check these –
Once you understand the cause, you can start the fix.
Here’s what we do at Nexyel for blacklisted domains:
If the blacklist issue does not get fixed, we sometimes recommend switching to a new domain for cold outreach. But that should be the last option.
After you recover from a blacklist issue, your next goal should be to avoid it happening again.
Here are the simple things we recommend to keep your domain safe –
At Nexyel, we set up systems that follow these rules from the start. That is why our clients get better results and fewer problems.
Prevention is always better than fixing a broken domain later.
Your domain is your digital name. If it gets blacklisted, it becomes hard to do any kind of email outreach.
Many people get stuck in cold email not because their message is bad, but because their domain is not trusted anymore.
That is why it’s important to check your domain often, understand how blacklists work, and know what to do if it happens.
Google Workspace and Microsoft 365 give you a strong base to start from. But even with those tools, your cold outreach can fail if you ignore blacklist signals.
At Nexyel, we help clients manage their domains, run blacklist checks, and keep inboxes safe. We also sell Google Workspace and Microsoft 365 licenses at a lower price, and we set up everything with the best practices for cold email.
So if you’re running cold email campaigns, or planning to start soon take domain health seriously.
Because once your emails land in inboxes, that’s when the real conversations begin.
