Email Marketing Blacklists - How to Prevent Getting on One

Email Marketing Blacklists – How to Prevent Getting on One

If you use email marketing on a regular basis then chances are you will have already had an IP or domain blacklisted.  It's important to understand that this will most likely be caused by your data collection practices, and so you should take time to review how you implement them.

How serious is being on a blacklist? Well depending on which one, you could simply be limiting a few email addresses, or it could mean almost complete shutdown of your email campaigns, and deliverability.   If we understand how blacklists work, we can use this to help address issues that put you there in the first place.

Below is a very helpful diagram, provided by Spamhaus, one of the major blacklisting sites.

To get onto a blacklist, you will have activated a spam trap.  If you have never heard the term, a spam trap receives email from you, and because the spam trap is known not be an active subscriber, the blacklist will then make assumptions upon your overall sending practices.


There are four main categories:

Old email addresses:

These are email addresses that were at one point in time valid, however have become dormant over a period of time. The ISPs will then usually bounce any messages sent to these back, maybe for over a year.  At which point they will then again activate the email for the purpose of operating a spam trap.


Typo email addresses:

This can be somewhat unfortunate, since it is where the email address is not typed correctly i.e. instead of These email addresses will never open or click an email. The assumption is that a large number of misspelled email addresses is indicative of poor list hygiene.


Newly formed traps:

These are email addresses placed around the internet to catch inappropriate list acquisition. The emails will never subscribe or join any list and will only be found where the list is generated from scraping etc. Poor quality purchased lists can often found to contain these types of traps.


User feedback:

These lists use actual emails from real users, who will join, open and click your campaigns. However, based on user feedback may classify your email as inappropriate or not complying with what they thought they would receive.  Based on this feedback again your domain or IP could be blacklisted.


If you find out you are inadvertently on one of these blacklists, it's important to get straight on to how you can get off them.  There are many tools around the internet to check blacklists, and confirm if your domain or IP is listed.  If you don’t have a delivery expert (which is why at 247EmailData every client has a contact assigned to help in these situations.) Then it is important to be proactive, the ISPs like to see you have made progress in a timely manner to get your domain and/or IP delisted from the blacklist.   Making contact with each blacklist can be time consuming, but if you find you are on one, it is important you make contact, and follow their suggestions for being removed.


Monitor your sending responses.  Low engagement with your list, high complaint rates, these are both easily identifiable signs that you may have issues with your list.  It can be costly, but if you are serious about keeping on top of these issues then reputation monitoring is key.  At 247EmailData we use our reputation monitoring to check on a daily basis, how your domain/IP is perceived by the ISPs.


As you can see it is much easier to prevent getting on to a blacklist, rather than having to get off one.  Here are some of the ways which will help you avoid spam traps.

  1. Confirmed - Opt-in: Being actually adding an email in to your active list, send them an email to get them to confirm they're subscription.
  2. Real time email address validation: Use a validation checker at the point of sign up, to get rid of those typo email addresses.


Blacklists although often getting a bad press.  Are actually here to make life better for everybody, by preventing unauthorised spammers from accessing the inbox.  If you use best practice and try to send information, that users request and desire, then you will avoid many of the pitfalls, and if you do end up on a blacklist, will certainly improve your chances of immediate delisting.