This article is written by Breanne Thorne. Breanne is a freelance writer & blogger.

“Could not deliver message to the following recipient(s):

Failed Recipient: [email protected]<mailto:[email protected]>

Reason: Remote host said: 554 fed1rmimpi309 cox 70.xx.xx.xx blocked. Error Code: IPBL0100 – Refer to Error Codes section at for more information.”

Or a short and simple nightmare

Access denied. Your IP address is blacklisted“.

If you are familiar with the pop-up mentioned above, feelings are likewise, and we feel your pain. We have been in a similar spot in the past but found our way back. And if you have come across a similar pop-up but were not sure what it means are those who are the chosen one and have never faced the issue, let me give you a little backstory of what I’m feeling.

What Has Happened?

Above mentioned is an error message that references that the IP address has been blacklisted, and you can no longer communicate or connect with the domain user. IP address means Internet Protocol address that is unique to every user on the internet.

It is a backlink for all the online activities done using a device (computer/phone/tablet/laptop or any other device) and network. When you work using Wi-Fi, your IP address is connected to the service provider (Airtel/Jio/Vodafone). Since they provide access to the internet, all your internet activities are tracked and back to you using your IP address.

An IP address is unique but not as unique as your personality, so don’t get attached to it and get it tattooed because it can change by merely calling the service operator or something as simple as turning your modem or router on or off.

IP Address Blacklisting

Now that you understand what an IP address is, let me explain the next thing – IP address blacklisted. Have you ever been so fed up by the constant spam emails you keep getting every hour, and you have I unsubscribed and even blocked just like then, they never message again? Well, that’s blacklisting.

An IP address is blacklisted when a hosting company ignores your messages, and all your messages are blocked and not forwarded. Huh! What a relief, no more spam emails. But that’s not it. Sometimes IP addresses are flagged by mistake or for an ignorable error.

Suppose you believe that this could be your case, and you want to find out why you were blacklisted. You’ll have to visit the blacklisted website and lookup for your IP address. If you can find out the reason for blacklisting, you can get it reversed. For that, you will need a technical guru!

In the meanwhile you find your technical guru, you can also try your hands on cracking the code to be-listing your IP address.

5 things to do when your IP address is blacklisted:

1. Removal Request

Few blacklists allow self-removal of IP addresses off the list without much hassle. But before proceeding with it, you must ensure that you have resolved the issue that had been raised on your address. In case you don’t fix it and the same problem or any other issue arises, and the IP address is blacklisted again, it would be difficult to remove.

2. Time-Based Removal

There are few blacklists that don’t allow the request to be removed but remove it after a duration of time, barring any further spam activity. They have built an automatic system that removes lower level listing within a week or two.

The volume of spam messages sent determines the duration of the listing. Higher the volume, the longer the listing period. If this isn’t your case and you need support, there are various websites than aid in removal from the blacklist

3. Involvement

The investment adds you to their blacklist and if your IP address is part of a range of IP addresses or domains classified as spammers. You must show that you haven’t sent any spam emails or proof that your IP address was misused or hacked by someone.

4. Spamhaus

Spamhaus operates with several blocklists. If your IP address is blacklisted, you enter your IP address in the removal center to determine the reason for the blacklist and step by step procedure and instructions for removal.

5. Barracuda

Barracuda works a bit differently. It requires your email address, IP address, phone number, and reasons for removing the blacklist. They thoroughly investigate the matter and process the request thereupon for removal within 12-24 hours of submission. It is done as long as a valid reason and explanation are offered.


If your IP address has been blacklisted, then it’s not the end of the world, and you do not have to worry excessively about it. Help yourself by knowing what is There are IT sassy people who can help you out, and in most cases, you are your savior if you try your hands and get it off the listing. Protect your systems from viruses and hackers and fix your security issues so no one can bargain and misuse it.