Email Blacklist

What is Email Blacklist: We’ll fetch you out from there!

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What is Email Blacklist & how to avoid getting there: Getting into email blacklist is among the commonest cause of email delivery problems. Once your domain or IP address is in the blacklist, you’ll indicate a surge in spam complaints automatically and hard bounces too.

All these will affect your brand reputation and, after all, a loss in the email open rates too. Therefore, using an Email Blacklist Checker is necessary for anyone in email marketing as the primary marketing strategy for lead generation and revenue.

Also, verifying your email list is equally important to maintain a good sender score to keep your emails secured from your subscribers’ spam folders. An email blacklist can be completed on two factors, in which one is the IP address of your mail server.

The second is the domain name of your email address, from which the emails are being sent. That is called “your from-address.”

Making a good customer engaging content is also a critical part of the email marketing strategy. However, forwarding emails at the same time to the relevant and verified user is crucial too. In case you don’t pay attention in curing making your emails fail-safe, then you might get blacklisted.

Are you a solid Email marketer? YOU SHOULD READ THIS:

What is Email Blacklist: We’ll fetch you out from there!

Sending emails with your blacklisted domain might result in reduced delivery rates of your emails. Numerous global mailbox providers like Yahoo, Gmail, and Outlook drop emails arriving from a blacklisted sender domain & assign a negative reputation score.

In this article, all your doubts regarding email blacklisting will be cleared. So, let’s begin!

How Do Email Blacklists Work?

Whenever you forward a message through email, it contains a set of digits called the IP address. The IP addresses rarely specify the server, which the email came from, type of like how a letter in a mail has a return address. Indicating the location of an email is possible by referencing the IP address.

When ISP receives an email, it automatically monitors the IP address against a blacklist. In case the incoming IP address is available on the list, the email will be simply discarded. If it’s not available on the list, it goes via some more spam filters before reaching the desired destination mailbox. The working type of these other spam filters is basically up to the ISP in question. In other words, a blacklist is only a tool, which determines whether an email should be received or not.

ISPs identify IP addresses, which are associated with forwarding spam content or sending emails to the email addresses, which are spam traps. The IP addresses are identified on the base of their history of sending good/bad emails. In case the IP address normally sends good emails, then it’s cleared for delivery.

Repeated offenses might land an email address on a blacklist. Besides that, even if your IP address has a good history but froward a campaign to an email list, which contains spam traps, then you’ll get on a blacklist in just seconds.


What are Various Types Of Email Blacklist Services

Fortunately, there are numerous sorts of Email Blacklist services, and you can pick one up on how they are reachable to the service using it. Shall we discover what they are?

Third-party Email Blacklist Services

Several independent companies offer blacklists as a service to various email services. For example, Gmail, Yahoo, email delivery services, spam engines, and so on. Besides that, they are widely available and also open to public use. You can check your listings manually. If you want to bring perfection, and rapid speed to the task, just tap, and it costs pretty low.

Now, if you wanna begin with the blacklist check service, we’ve noted some popular email blacklist check databases.

List of Popular Email Blacklist Check Databases

For checking your domain listing in the database of the blacklist, here are some famous methods to know in which you can look up your domain or IP name in:

  • Composite Blocking List (CBL)
  • Spam and Open Relay Blocking System (SORBS)
  • Senderbase
  • Spamhaus Block List (SBL)
  • Spamcop
  • XBL Exploits Block List
  • Invaluement
  • Passive Spam Block List (PSBL)
  • Barracuda
  • SenderScore

Most of these databases of a blacklist of IP addresses & domains also incorporate the addresses of known spammers, proxy servers, open SMTP relays, and zombie computers, which are compromised via hackers and malicious code.

Email Blacklist Categories

An email blacklist is normally divided into 2 categories relying upon which identifier is in use to identify the spamming source.

  • IP Blacklist – Each server has the IP address, which defines the location it has on the internet. As for the emails you have, they are forwarded from the email delivery service for getting sent to the receiving services like Gmail. The public servers’ IP addresses that are known to forward spam emails, which are infected with botnet or might the servers are acting as an open relay are frequently added to the IP blacklist.
  • Domain Blacklist – Each email that you forward contains a domain connected with it, this domain is known as email sending domain. You can see this domain in Return-address, From-address, and in the DKIM signing domain too.

In case emails which are sent by these domains are taken as to be spam emails on the basis of the sending habits & history of email sending, they can be easily added to the email blacklist.

What now?

Now you’re familiar with the different services providing email and IP blacklist. Now, shall we check and remove your email from the blacklist? No. Permanent removal of your email from the blacklist includes more things than just simply asking for delisting your email from any blacklist. You need to understand the methodology, as understanding the source of the disease is important before taking any medicines.

For knowing how to solve your email blacklisting issue, you should know, after all, why does it happen and what are the identities and services responsible for your IP or domain is listed into the blacklist. Hence, we should cherish blacklist authorities, influencers, and entities responsible for listing you to any blacklist and on what grounds they do it.

How We End Up on a Blacklist?

Now, possibilities are there that you might be sending only good quality emails, but still, you suffer. The fact is even a little mistake can very easily get your domain blacklisted. For instance, in case your list isn’t opt-in, and it’s procured from a few external sources, then there are huge chances of your list containing spam trap email addresses. If you hit spam trap email addresses frequently, it will get your sending domain, and IP address immediately blacklisted on multiple DNSBL services.

Anti-Spam vendors, MSPs, ISPs, and even the general recipient user of your email can highly impact the blacklisting of your email sender domain/IP address. Now, let’s understand the cases closely.


The Mail Service Providers (MSP)

MSPs can be described as the email services providing you with email inboxes such as Outlook, Zoho Mail, Gmail, Yahoo Mail, and so on. All these services are in a continuous view of the suspicious emails and will save no one if they find that the mails are spammy, no matter its ESP or an individual. These services use numerous resources to filter spam emails such as Domain Name Status List, Third-party Email Blacklists, Anti Spam Engines, and Email Policies that define how they’re going to behave against particular sorts of emails.

The Email Recipient

The Email Recipient passive influencers of the email blacklisting, and that’s a thing to note down. The open SMTP protocol permits the sending of any sort of email to any of the recipients. There isn’t any restriction or protocol-level check. Despite having tons of anti-spam software in the market, it’s challenging to catch-hold all types of spam.

To avoid spam, several MSPs provide a button like “Report as spam,” which acts as open polling. In case there are enough such reports raised against your email, then surely, the chance of your domain getting pasted to the blacklist is very high.

Spam Traps or HoneyPot Email Addresses

You might come across email addresses that look just like a normal email address, which are primarily owned by various MSPs and anti-spam agencies. They distribute such trap email addresses throughout the internet to catch if someone is sending emails on non-opt-in receivers.

The majority of the third party/harvested email list contains some spam trap email addresses. Even if you hit a single spam trap, it can affect the real-time blacklisting on your IP address and domain, and affect your overall reputation as a sender.

Even though there are numerous sorts of Spam Traps, which are mainly divided into two base categories.

  1. Recycled Spam Traps: These email ids are abandoned/unused for a long time or simply closed accounts, which are mostly used by ISP. However, these are less strict when it comes to adding you to the blacklist. These will still damage your domain reputation.
  2. Classic Spam Traps: These email ids are primarily created to normally blacklist anyone involved in sending emails to these email id.

An Instant Incline In Email Volume

Most marketers make this common mistake.

Inclining up of your email volumes can be taken as an alert sign that you’re actually sending emails to an email list that you did not build on your own. However, you have got it in bulk from any external source or after paying someone. Simple logic says- How can you get so many subscribers in just one day?

After saying that, the market is now in much more control of the email blacklist in comparison to what you are assuming. They are utilizing smart DNSBL services and also have their own sets of rules for blacklisting.

Talking about the DNSBL service, it’s not only a constantly updated directory consisting domains but like a software environment that elaborates in close conjunction to the DNS (Domain Name System) of ISP, which are involved in mapping your Domain name, IP address, and vice versa.

Do you need to worry about that? We have come across a scenario when you’re listed on the blacklist. However, not the way it’s seen by numerous services that utilize it.

With your IP/domain being blacklisted, does everything halt there? Has everything finished? Can you send emails after being delisted only? Well, it depends. To kill that question, we have to cherish how the MSP and ISP work with DNSBL and act with emails from blacklisted IPs and domains.

Some other big reasons which get you blacklisted

The reasons discussed above were the most common ones, but that doesn’t mean the list of the reasons end up there! Email marketers try their hand and leg today. To generate business, and in such cases, the system also needs to be strict, right? Here are some other common activities that can harm your sender reputation. Also, it might land you on the spam folder or blacklist.

  • Poor email list hygiene: If you’re sending tons of emails to inactive addresses or spam trap inboxes, then it’s ugly for your sender reputation. Several ISPs use harvested emails as spam traps. If you send numerous emails to these types of accounts, it will reflect poorly on the email sourcing practices of your company.
  • Hackers: Hackers might have gotten access to your email account to send spam messages and damage your reputation. Also, hackers (or your dirty competitors) could be spoofing your email address. It means they are using your IP address to send fraud emails and pushing you towards blacklists. If you rectify many error messages for emails that you actually didn’t send, then definitely someone is spoofing your account, and you need to take action.


  • Enhanced email volume: In case an ISP indicates a sudden spike in email traffic arriving from your IP address, it might take that as a sign of spam content. Organizations that are legitimate usually build their email list gradually over an extended time & sudden spikes seem very suspicious.
  • Bad email content: Numerous ISP filter emails by keywords indicated in the body of the text. Words such as “free” “money-back guarantee,” colored fonts, CAPS LOCK, and tons of exclamation marks (!!!) are considered all red flag content, which might get you to put on a blacklist.
  • Failing to handle email list: in case the email list you have is unmanaged and you constantly do not honor the request of individuals to unsubscribe, then there are high chances of your IP to get in an email blacklist.

ESPs depend on being able to forward tons of emails, so they normally try to handle ISP blocks themselves. In case your email is the culprit, though, they might have some questions for you.


What Are Some Signs Of Being Blacklisted?

In case you are on the blacklist, then you can’t forward emails to the recipient’s mailbox correctly. Mostly, it can be dropped at the MX server of the recipient, giving you a bounce code. However, does that mean you’ll completely be blacklisted from each mail server in this world? Simple no!

Even in case you are blacklisted on a specific DNSBL service, there are numerous other email blacklists available on the internet. Non-delivery of your email entirely depends upon whether the server of the recipient is your case and is referring to that specific DNSBL or not where you are blacklisted.

In the other scenario where the MSP or ISP is not using the blacklist, which you are listed on, then there’s are high chances of the probability of your sending domain/IP address won’t get marked like a suspicious spammer. Anyways, you have to know regarding MSPs that it can have other email mechanisms too for filtering out spam emails other than only blacklists.


For example, some MSPs think your past emailing history & engagement on those emails like a key parameter fro classifying or reclassifying the domain/IP you’ve as blacklist as well. To summarise it, here are some examples, which indicate you might have an issue with your domain/IP being marked as an email blacklist.

  • An enhancing number of Emails being dropped.
  • Delivery rates deterioration
  • A huge number of Email bounce rates

However, these are not enough to ensure you being blacklisted, only some alert signs. With delivery issues’ clear signs and some drastic drops in email delivery, you can now move further to indicate and ensure the blacklisting of domain/IP address. Now, let’s move further on how you can know in case your emails are blacklisted or not.

What’s The Process of Knowing is My Emails Are Blacklisted?

Now is the time to ensure your listing in the third party services of blacklists. But where to indicate? One of the approaches to check whether you’re blacklisted or not is to check some obvious signs, just as described in the above section. There are basically two ways to identify your email is blacklisted or not.

Bounced Emails

The worst turn about your domain or IP being blacklisted is that emails probably get dropped & bounced. In case you’re worried about your emails getting dropped and blacklisted, don’t be, and identify your bounce back emails. The biggest blacklisting services and ISPs offer SMTP error codes mostly on the bounce back emails to make you understand the reason for being added into the Email blacklist. You can identify on the base of the SMTP error codes regarding why the emails were blacklisted in the first place.

Some services offer a panel where they show you’ll of the SMTP errors from the domain you have. To indicate, firstly, you first have to signup for their services, and that is totally free. There you can identify the status & reason for your emails being dropped by indicating their SMTP error code table. In case this is too much hassle, checking just these SMTP errors in your email servers log is possible too.

Identifying your IPs and Domains in Email Blacklist Directory

In case you think to identify your email blacklisting in the ten or so RBL service is enough, then you are wrong. There are numerous types of email blacklist services available on the internet. Identifying manually in all of these services is actually not a practical solution. It will take numerous days to identify all of them.

To save your precious time, there are services available on the internet. They can handle a list of real-time RBL directories to search your domain/Ip address and identify in case you are on the list or not. They even offer a page dedicated to that specific RBL service detailing the kinds of RBL lists they use and a few links to assist you in delisting the domain/IP address you have.

Here is a list of the famous lookup tools to identify the domain blacklisting on numerous DNSBL lists:

MultiRBL: This is a basically a ree DNSBL lookup site, which scans on 100+ DNSBL lists to identify for domain blacklisting. It also indicates the details regarding the listing as well as steps to eliminate your domain from the blacklist.

MXToolBox: Similar to MultiRBL, this service is another tool, which checks for blacklisting of the domain you have in numerous RBL List. And it too offers detailed info for the blacklisting. MXToolBox also offers suggestions on your domain’s live status & blacklisting.

There are other services for identifying email blacklist too. However, these 2 are the basic and free ones that you can get and start monitoring your blacklisting status constantly. Then you can go further to research numerous other prominent services you can locate to add in your list the more, the merrier.

Third-Party Blacklists:

You can also identify into the individual lists of RBL services fro example, Barracuda, Spamhaus. They will offer you highly detailed information about listing.

Ok, you’ve found out that you’re indeed listed into the DNSBL list, and now you want to eliminate your domain or IP immediately from the list. Now, let’s move further? Well, hold on. Before you request delisting of the site you have, you must fix the problem that got you on the blacklist firstly. With the next section’s knowledge, you can deal with this.

What’s The Procedure Of Getting My Email Off The Blacklist?

  • In case you’re handling your email delivery, then identify your return path/abuse-mailbox, in case your domain is on the blacklist. You may have got an email for this that you’re on the blacklist from the DNSBL list owner, as well as a link to delist the name of your domain from the service.
  • If you’re using a few Email Service Provider (ESP), then contacting the service is good to assist your domain to get out of the blacklist.
  • A few RBLs automatically do listing & delisting according to the last time of blacklisting. That means in case you have been added on their blacklist. They wait for a specific duration of time to delist the site you have automatically. This works only in case no repeated listing was made on your IP in that specific time duration. The time duration to delist might vary depending on the service. So stopping the emailing activity completely and resolving the issue is what you must do that got you in the blacklist. After the problem being resolved, you’ll be automatically eliminated from the database if you’re not listed ones more.
  • You can also contact the blacklisting service directly via email.
  • The domain blacklisting services frequently have a delisting form if you want to delist the IP or domain you have from the blacklist. Just add in the form with the name of your domain and contact details. After that, add a valid reason for delisting. The reason must be that whatever scenario which has got you on the blacklist has been solved.

Important Notice

Requesting delisting to the blacklisting authority is compulsory, only in case you’ve fixed the issue that got your email/IP listed in the first place. If you don’t do so, it’ll land you in that blacklist again no matter you’re the delist once.

Also, do remember that a few blacklisting services won’t permit you to delist your IP/domain in case you’re frequently on blacklist several times. So ensure cleaning your act before you make the delisting request.

How to lookup for your domain/IP?

To summarize the same, here we provide some simple steps that you generally have to take for getting your IP / Domain address out of the blacklist.

  1. Lookup into the MULTIRBL or DNRBL site for your IP address / Domain.
  2. After getting yourself listed, check the recommendations that RBL or Multirbl site provides.
  3. Fix the issue that dragged your listing in the email blacklist.
  4. Fill a Delisting Form to request delisting, or you can directly email to the listing service.

With all that hard work and research, you’ve got yourself removed your email/IP from the email blacklist successfully. But, can we really just stop here and promise that you won’t be blacklisted in the upcoming time? The answer is a straight “No.” You can take precautionary measures while moving ahead from here. To avoid thrown into the blacklist again, a few of them are mentioned in the upcoming section.

How Does Avoid Being Added To Email Blacklist in the Future?

Prevention is certainly a well-needed continuous process. It’s never gonna stop because preventing yourself from getting blacklisted is a good habit you need to force yourself to follow while sending bulk emails, be it promotions or marketing. Here are a few which we’ve listed for you to kick-off, and take you to develop good email delivery habits.

1.) Send emails to only and only opt-in user list: Practice adding users via self-initiated subscriptions only.

2.) Avoid procuring lists from external sources: The big fact is – 92% of the list you buy from external sources consists of spam traps. As discussed above in the guide, these spam traps are the biggest influencer for your IP or domain to get blacklisted.

3.) Respect un-subscribers and don’t retarget them: If you send emails to unsubscribed users, it leads to an increment in Spam Complaints. If such patterns increase, it will ultimately result in email blacklisting.

4.) Remove bounced/inactive email addresses from your daily mailing list: Not working with the bounce email notifications among the biggest signs of a company not rolling according to the email sending guidelines, and that’s how they get marked as blacklisted by either the ISPs or MSPs.

5.) Avoid sending emails via an open relay SMTP server: using Open relay SMTP server for sending emails brings nothing good, as it’s an email server that’s open for everyone to use without any authentication or restriction. Understandably, spammers love using these email SMTP relays for the purpose of sending bulk spam emails. Hence, it’s undoubtedly bad for you in case you’re using the same SMTP relay server, and you might end up in blacklists.


6.) Target users by creating Smart segments: Carefully figure out hat’s your target audience, and narrow them down into categories. Further, send emails accordingly. That reflects taking the time to perfect design and plan your campaign for various user groups you’ve targeted.

7.) Avoid a dramatic increase in mailing volumes: Being hasty will backfire for you here. Rather, increase it steadily and slowly. If a company is sending irregular patterns of emails, then it’s a clear sign that it’s sending emails on a third party list that they purchased, and it will raise alarms at the MSPs level. Following the email, the warmup process is the right thing to do before sending emails at scale.

8.) Weekly monitor your IP/ domain reputation: Monitor your domain and IP’s reputation on numerous tools like MultiRBL, MXToolBox, and there are tons of them.

9.) Create values rather than selling: If your email content sounds like direct marketing or forced marketing innuendo, it won’t work for you.

10.) Create your email content to appear less like a Spam mail: You need to market emails using the user content. Things including email size, email text, and email body structure define how your email will be considered and perceived by spam engines. It’s fairly important, and no matter if you follow just good practices while sending emails. A bad email can directly land you in spam in no time.



The ideal way of reducing your risk of being a part of a blacklist is different for various business models. Blacklists don’t exist to difficulties to email senders’ life. They’re here to just help block spam and keep recipients glad.

Remember that the email blacklists’ motto is to prevent email from delivering to inboxes that didn’t get recently opt-in to receive an email with informed and explicit consent. Hence, no single preventative measure guarantees zero blacklistings. However, it also means that in case you’re doing everything correctly to send an email that people really desire. It will surely make the process of getting yourself delisted that much faster and easier!

A Golden tip that can save an Email marketer from getting blacklisted

As we mentioned above, you need to play safely in order to avoid entering the blacklists. There’s a golden solution that decreases your effort to almost 70%-80%. 

Figuring out whether an email is authentic or not is challenging. If you sit manually to do that, you’ll spend ages doing that! An Email Verifier tool can highly automate the whole process and ensure perfection. After that, if you’re writing your emails well, and following just a handful of ethics, then there are hardly any chances of ending up your IP/Domain into blacklists!

Do you know which is the most Accurate Email verification tool out there? Well, it’s none other than MyEmailverifier, which does a better job than any other in the industry. Even Yahoo email filtration is there, and you get all clean lists. That’s how you’ll increase conversions as well, won’t you?

Just tap MyEmailverifier, and you’ll get to learn much! The price is low enough to drop your jaw!


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