What is a Blacklist?

Blacklists are generally used by organizations, such as Internet Service Providers (ISPs), free mailbox providers, and anti-spam vendors to prevent spam from entering their systems. An IP or domain can be blacklisted based on the quality and quantity of the emails sent. They can be either internal blacklists created and used by very large ISPs, but the majority are publicly available and run by companies that specialize in this field.

Let’s imagine you (the sender) want to send a Newsletter to your audience. Your emails are received by an ISP (the receiver), who decides whether they look legitimate by checking against their blacklist if the IP address of the emails is recognized. Then, the emails go through the spam filters of the receiver. If they don’t violate any criteria, they are successfully sent to the users’ inboxes. An ISP subjects an email to many of their policies and a blacklist represents just one of those tools used to decide their legitimacy.

It is enough just to use a bad email list and get a high spam rate, in order to get your IP address added to a blacklist. Spam complaints are generated when someone marks your emails as Spam, which in return triggers the ISP to flag your email content or email list as bad. High bounce rates can also indicate to the ISP that the emails are not opted in or that the list is old and needs a clean-up. The size of the email list and its growth rate can be a trigger also for ISPs. Usually, healthy email lists are grown organically over time, with every new customer or lead that signs up for your Newsletter. Having a list that grows substantially in a very short period of time is an indicator for most ISPs that the list was purchased. And guess what? This will make your IP address or domain a strong candidate for the blacklist.

• Send Relevant content - Refrain from sending out blanket emails to all subscribers in your audience. Blanket emails are standard emails sent to more than one user at a time. Instead, send personalized emails with dynamic content
• Watch your statistics - Keeping an eye on any drastic drops in the open rates of your emails is important, as it might suggest to you that you need to check on your blacklist status.
• Use your own email list, that you have grown organically - In other words, do not buy an email list, as it can do you more harm than good in the long run. Getting off a blacklist is harder than getting on it. The best advice is to patiently grow your own email list because those are the customers you can count on to build trust and loyalty with your brand.
• Keep your email list healthy - If you already have a substantial email list, you should make sure you do periodical clean-ups, as some addresses become inactive over time or people just lose interest in your brand. You can either win them back or let them unsubscribe themselves if they are not interested in what you are offering anymore.
• Use audience segmentation - Not everybody might be interested in the same product or category of products at the same time, so make sure you segment your audience accordingly, in order to send the right message to the right person at the right time. There are many options for segmentation such as buyers, non-buyers, brand affinity, active and inactive users, etc.

When your IP address is blacklisted you need to contact the list to get it removed. Every major blacklist organization has information on their website on how to get it removed from their blacklist. Just follow their instructions on how to clean up your email list.

If the email list is smaller and you make sure you are following best practices to avoid spam complaints, you will be dropped automatically off the blacklist after a while. You can use tools like mxtoolbox.com to check whether an IP address is blacklisted.

If you are using an email service provider, they’ll make sure to inform you accordingly on what to do to get back on track with your list and they will contact the blacklisting companies to request their IP address be removed in order to continue sending. The only disadvantage is that you may have your account blocked/ inactive until you have cleared your list.