How to Keep Your Domain Off an Email Blacklist

Marketers put much effort into crafting messages. They design templates, think of subject lines, write copies and create visuals. They also set up the audience, segment subscribers and plan sending schedules. And naturally it can’t but discourage when your email campaigns don’t reach their destination that is the customer’s inbox.

This may happen for several reasons, and your domain being on a blacklist is one of them. Even if you’ve collected your contact base the legal way and don’t send malicious software or explicit content, you can end up among spammers. Restoring your reputation is always a hard and time-consuming job so your task is to avoid blacklists in the first place. Let’s see how to do it and protect your name of a reputable sender.

What Is a Blacklist

A blacklist is a list of IP addresses that are identified as ones sending spam. The list is updated in real time meaning an address can get into it at any time. Senders with a good sending history can get blacklisted if they start to deliver malicious or poor-quality content. Blacklists are used by email clients and email service providers to protect their systems and users from spam.

If speaking technically, a blacklist is a filter algorithm that checks several parameters to determine whether to block a certain IP address. Among others, these parameters include your previous sender reputation, the quality and quantity of emails you send, subscribers’ engagement with your content, bounce rate, unsubscribe rate, and spam reports.

Email clients and providers can have different spam algorithms but variations are minor. Also, there are special services, the so-called spam databases (Spamhaus, MX-Toolbox, Sender Score, etc) that run and maintain different kinds of blacklists. These lists are publicly available and can be used by ESPs and businesses. You can use them to check if your domain is on a blacklist.

What Is a Blacklist

Domain reputation check by Spamhaus

Basic Steps That Will Keep You Off Blacklists

The below 3 tips are only the tip of the iceberg when it comes to keeping your domain off the blacklist trouble. But by following them, you’ll build a solid foundation for further campaigns.

Don’t use a bought contact list.

This is an issue of marketing beginners who only get started with email campaigns. Building a contact list is time-consuming and many don’t want to wait and decide to use some help on the side. They buy batches of email addresses and start sending them.

However, you need to understand that these are just random addresses that have no relation to your brand. Many of them can be fake, invalid or spam traps. You may clean the bought list with an email validator and extract only real addresses but it won’t make their owners interested in your service.

With the bought list, you will be sending to strangers who have never heard about your brand and haven’t subscribed to your campaigns. Some of them may ignore your messages for a while and unsubscribe if you’re too persistent and send too often. Others may straight report you as a spammer which you actually are when sending without permission.

Aside from harming your reputation and killing your open rate, you’ll be also wasting your budget on irrelevant prospects. It’s always better to grow your base step by step than to buy shady lists with none of your target audience on them.

Use double confirmation.

Double Opt-In (DOI) is a double-step confirmation. Users who fill in the subscription form receive a confirmation email and need to confirm their email address. Only users who confirm it are added to your contact list and can be sent promotional emails to.

DOI is an official requirement by the GDPR and other customer privacy policies, yet many brands still ignore it. They think that confirmation is an extra step that complicates the signup process and that some users can be lost in between the form filling and email confirmation. In fact, DOI protects your email list from low-quality contacts, bots and spam traps.

As a result, you’ll be sending to people interested in your offers. They will expect messages from you and will be more likely to open them and engage with the content inside. High subscriber engagement is a signal for email clients that you’re a trustworthy sender, meaning your emails will less likely end up in spam.

Basic Steps That Will Keep You Off Blacklists

Confirmation email by Maniology

Grow the sending volume steadily.

Sometimes brands collect contacts but don’t send any campaigns or send too few and too irregularly. And then suddenly they decide to get serious about their email marketing and start sending 7 emails per week to the whole base, say 10,000 contacts. That’s not a very good idea.

To email clients, domains with too sudden and massive activity look suspicious. Since spammers often blast emails from new domains, your emails can get labeled as potentially malicious.

To avoid Inbox quarantine, warm up your domain steadily. Start sending limited batches on several days and increase the sending volume and the number of campaigns. For example, start with 1,000 emails in the first two weeks; then send 2,000 emails over the following two weeks and add 2 thousand emails every two weeks until you cover all your contact base.

Add the unsubscribe link to your emails.

Even people who have subscribed to your list according to all rules may want to leave it. Reasons vary. Some are no longer interested in your product. Some get tired of the type of content you’re sending. Some switch to your competitors. Whatever the matter, you need to let them go.

To make the separation process less painful for both of you, add the unsubscribe link to all emails. Don’t be afraid that its mere presence would prompt people to unsubscribe. As long as you send relevant content, your target audience will follow you. And those willing to part will do it one way or another. And it’s better for you if they do it through the unsubscribe link than through the Report spam button.

Grow the sending volume steadily

Unsubscribe link in the footer. Email by The Celtic Manor Resort

To Sum Up

The main advice that will keep your domain off blacklists is to take it steadily. Building a good domain reputation is a long process. Grow your contact base through subscription forms. Warm up your domain. Don’t start with sending too many emails within a short period of time. Follow the customer privacy policies and respect your subscribers’ preferences. This way, neither email clients nor your audience will have any reason to doubt your good name.

Author’s Bio

Author’s Bio

Iuliia Nesterenko is a technical writer at eSputnik. Her focus is on exploring current digital marketing trends and describing new strategies for email marketers.


Ehacking Staff
With more than 50 global partners, we are proud to count the world’s leading cybersecurity training provider. EH Academy is the brainchild of Ehacking, which has been involved in the field of training since the past Five years and continues to help in creating professional IT experts.

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