Email blacklisting is a critical issue that can severely impact your ability to communicate effectively with your audience. For businesses and marketers, being blacklisted can damage your reputation, disrupt email campaigns, and render your plans useless. So, understanding the causes of blacklisting is essential to maintaining a healthy email-sending reputation and ensuring seamless communication.
In this guide, we’ll learn what an email blacklist is, some common causes behind blacklisting and how to avoid getting blacklisted.
What is an email blacklist?
An email blacklist or DNSBL (Domain Name System Blacklist) is a list of those domain names or IP addresses that are flagged as sources of spam or malicious activity. It is essentially a real-time database, therefore also known as RBL (Real-time Blacklist).
The email blacklists aim to prevent unwanted spam content from reaching users. Mailbox Providers such as Gmail, Yahoo, and others use blacklists as a filtering mechanism for detecting and blocking spam emails. Likewise, Internet Service Providers (ISP) and Anti-Spam Agencies (ASA) also refer to these blacklists.
The email blacklisting practice can adversely affect email marketing campaigns. Being put on a blacklist can cost a lot to a company as it can drop their entire email deliverability rate. When a brand's domain name or IP address is blacklisted, its emails end up in the user's spam folder instead of inbox. Let's have a quick look at who maintains the email blacklists and how you can avoid getting on one.
Types of email blacklists
Depending on the what gets blacklisted, blacklists can be majorly divided into two categories:
1. IP Blacklists: Block emails from specific IP addresses associated with spam or malicious activities.
2. Domain Blacklists: Target specific domains linked to spam or phishing emails.
Who maintains the email blacklists?
There are 2 major types of email blacklist with respect to who they're maintained by:
1. Public blacklists
The public blacklists are available for and accessible to all. Anyone can check these blacklists through different tools like Spamhaus, Spamcop, Hostkarma, etc.
2. Private blacklists
Some major mailbox providers such as Gmail and Yahoo maintain their private blacklists database. They use these internal lists to filter spam. Unlike public blacklists, which are shared across multiple platforms or organizations, private blacklists are unique to the entity maintaining them and cater to their specific security preferences.
Why do you get blacklisted?
It has been observed that companies often land up being blacklisted despite the best technical software and practices. Some of the reasons for blacklisting could be:
1. A huge number of spam complaints
ISPs and email service providers tend to blacklist your address if your recipients mark your emails as spam. This could be because you’re sending irrelevant content or they haven’t subscribed to your emails or your sending emails too frequently.
2. Spam traps
ISPs use spam traps to track spammers. There are three types of spam traps: recycled spam traps, new spam traps, and typo spam traps. If your email lands in a spam trap, it gets marked and if it keeps hitting these spam traps beyond a permissible limit, it will get blacklisted.
3. Unauthorized access and malware infection
If hackers get access to your email or your domain, they might also spoil your sender reputation by sending spam emails from your email address. There would also normally be a spike in your email activity, which would further signal that ISPs of the unusual behavior. This would lead to blacklisting. This spike could also happen if your system is infected by malware. Emails sent through the infected systems will not pass the spam filters, thereby not reaching the desired destination and triggering the blacklists.
4. An unexpected increase in list size and bounce rate
The ISPs can suspect the companies purchasing the email list by the unexpected hike in their email list size during a short period. Sending to invalid or inactive email addresses also adds to this suspicion. Hence, they can put these IP addresses on the blacklist.
💡 Related read: How Does Your IP Address Affect Your Email Deliverability?
How to avoid getting on the blacklist
As a marketer, you should avoid getting on the blacklist to make your email marketing campaigns successful. You must employ the best strategies to make your emails pass through the spam filters. Here are some best practices:
1. Add double opt-ins
Double opt-ins are a two-step verification process for confirming the subscription on the part of the recipients. This will help you reduce both fraud and spam complaints. It will also allow uninterested parties to opt-out of the subscription, thereby maintaining a clean email list.
2. Never purchase email lists
There are high chances of you falling prey to the spam traps set up by the ISPs in case you choose to buy the email list. Moreover, bought email lists have a high chance of containing old, and illegitimate email addresses. Additionally, the people on the lists might not even know that their emails are being distributed and would usually not have consented to receive emails from you.
3. Maintain email list hygiene
Email hygiene is an essential factor here. Implement a sunset policy and remove old and inactive email addresses from time to time.
4. Build high-quality content and monitor engagement
Provide relevant and high quality content to your recipients. You must include the latest interactive content with a personalized touch in your emails to keep the users engaged. Monitor the performance through data analytical tools. Pay close attention to the email open rate and click-through rates metrics and noticeable changes, if any. Add one-click unsubscribe, as it can help filter out the uninterested recipients.
5. Be consistent in your email sending frequency
Consistency is a crucial element for audience retention in the long run. Stay consistent with the frequency of emails you send. Overall, add as much value as you can and provide them with what they're looking for!
💡 Related read: What Is Double Opt-In and Why You Should Use It
How to find out if you are on a blacklist
These days, numerous databases maintain track records of spam IP addresses and domain names. Blacklisting checker tools work by querying DNS (Domain Name System) records to see if an email address or domain is listed on any blacklists. If a match is found, the email is flagged as spam. Below are examples of some of the best blacklisting checker tools.
What to do if you are on an email blacklist?
Usually, the ISPs maintain as small blacklists as possible to keep the emails flowing. So, there is nothing to worry about, even if your address appears on one of the blacklists. Around 15% of the email marketers said that their companies' email addresses had been blacklisted at least once in the last twelve months.
Well, most of the email service providers contact you and run you through the process of getting it fixed. They also reach out to the blacklisting services company to get your name removed from their lists. Alternatively, you can contact those companies who have blacklisted you. You may even have to follow their necessary recovery/email blacklist removal process and follow some instructions like cleaning your mailing lists, etc.
Wrapping up
Blacklisting is a common issue with companies running email marketing campaigns. What matters is you learn the rules of this game to ensure none of your campaigns fail in the first place. Keeping in mind the tactics discussed in this article and designing the strategies wisely can reduce the probability of you getting blacklisted.
Additionally, interactive content is the best way to nurture long-term customer relationships. It decreases spam complaints and increases email deliverability and click-through rate. What are you waiting for? Check it out now.
