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Run a Thorough Email Domain Health Check with These 6 Steps

In a world where email marketing is projected to generate a staggering 11 billion USD in revenue by the end of 2023, ensuring the health of your email domain is paramount.

Think of your email domain as the beating heart of your email deliverability, pumping vitality into your marketing campaigns. Just as a healthy heart ensures smooth blood circulation, a robust email domain's health guarantees the seamless delivery of your messages to their intended recipients.

At Folderly, we believe that a dedicated approach to email deliverability by checking its essential 6 building blocks is not a recommendation but a requirement. This is the first step we take to help our clients reach 100% email deliverability.

In this comprehensive guide, we equip you with essential tips and insights on conducting a thorough email domain health check, empowering you to harness the full potential of your email marketing endeavors.

How To Check Every Component of Email Domain Health

The biggest misconception is believing that an email domain health check can be done in a few clicks with online email marketing tools. We wish it was true. 

To conduct a thorough health check, you need to examine how every part of your body functions. And the same is true about email health. 

To go beyond a quick examination of your email deliverability and get your email domain health score, you need to check its 6 building blocks.

But, considering the predicted revenue, isn't your email health worth it?

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DNS records Checkup (DKIM, SPF, DMARC, BIMI)

First things first, DNS records are the fundamental components of the Domain Name System. In fact, the number of DKIM keys observed tripled from 2020 to 2021, and continues to grow.  DNS records are critical in managing how your domain name operates and interfaces with various systems across the internet. So, it makes sense to start by checking their functionality. 

DomainKeys Identified Mail (DKIM)

DKIM is a record that acts as a digital security guard. Its primary role is to protect your reputation from scammers and phishers who seek to misuse your trusted name to disseminate harmful content. It attaches a unique encrypted signature, visible to receiving servers.

➡️ How to check: You don’t need a complex DKIM validator to test your DKIM signature. You can do everything right in your Gmail web account:

Step 1: Open your Gmail web app
Step 2: Send a message to your Gmail account
Step 3: Go to the “More” icon and choose “Show original”
Step 4: Look at DKIM field and if you see PASS, it means your DKIM record is set and sound. 



If you want to dive deeper and learn how to address potential issues, here’s a detailed guide from our experts on how to check DKIM Record.

Sender Policy Framework (SPF)

Consider SPF, or Sender Policy Framework, as the bouncer at the doorway of your email domain. Its task? Ensuring that only the 'right' addresses get the green light to send emails from your domain. Considering that at least 1 personclicked on a phishing link in around 86% of companies, it's a must-have barrier, standing tall against scammers and phishers who might attempt to use your domain to dispatch unsolicited emails or malware.

➡️ How to check: To check your SPF record with Google Admin toolbox, go to its and

Select Check MX in the menu. This is your go-to option for checking up on your domain records and verifying that your DNS settings haven’t been compromised.

Also, you can use the online SPF Record Check by MXToolbox is a diagnostic tool that acts as a Sender Policy Framework (SPF) record lookup.


Extra tip from Folderly: You need to ensure you update your SPF record every time you add or remove a tool that sends emails from your domain. If you list more than one domain, you will have to create a separate SPF record for each manually. 

The best way to update it quickly is with our free SPF Generator.

Also, we have a comprehensive guide on SPF records where you can learn how to create an SPF record, set up it, and which serious mistakes are better to avoid.

Domain-Based Message Authentication, Reporting & Conformance (DMARC)

Domain-Based Message Authentication, Reporting & Conformance (DMARC) is the protocol that covers both DKIM and SPF and demonstrates them to Internet Service Providers to confirm that your domain is not used for spoofing and phishing. 

Basically, it’s a set of records. 

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➡️ How to check: Just like with SPF, you can use the online DMARC Record Check by MXToolbox to check your current DMARC record and identify potential problems. Also, you can dive deeper to learn what is DMARC record in detail with our comprehensive guide. 



Brand Indicators for Message Identification (BIMI)

BIMI is a company's logo, standing next to each incoming email in your recipient's inbox. It's a potent weapon against fraudulent senders who flout email compliance. Often perceived as DMARC 2.0, BIMI collaborates with DMARC, DKIM, and SPF, forming a robust defense system.


➡️ How to check: BIMI checkup is available on MXToolBox as well. Just type your domain name and get a quick overview of your BIMI record's current state.


Checking Blacklist Listing

Are you ready to take another proactive step towards maintaining the health of your email domain? A domain blacklist is a listing of domains suspected of sending spam. Frequently, Email Service Providers (ESPs) leverage these blacklists to scrutinize and identify spam domains in the main message.

But it's not just domains that can be blacklisted. Your IP address can also find itself on this list. IP blacklists consist of IP addresses believed to be spam email offenders.

We have a detailed guide on how to remove domain from blacklist (and for such major blacklists as Spamhaus Blacklist and Outlook Blacklist). 

➡️ How to check: Head over to MxToolBox or Blacklist Alert, two reputable platforms, for a swift and efficient blacklist check. While manually visiting every major blacklist is an option, these blacklist monitors can evaluate your domain against all major and minor blacklists within seconds: 


Check Simple Mail Transfer Protocol (SMTP)

It's always wise to ensure your SMTP is functioning optimally for the health of your email domain. SMTP is a set of rules and guidelines that enable your device to send and deliver messages over the Internet. It’s one of the other email protocols (POP3 vs IMAP vs SMTP).

In essence, it serves as a rule book, a protocol that guides the sending and delivery of messages over the internet. It's akin to a language, facilitating communication between your computer, the sending server, and the recipient server, guiding them on how to handle your message. Without an effective SMTP, your email address could inadvertently end up on a blocklist, often unbeknownst to you. SMTP protocol becomes particularly crucial for those involved in bulk emailing, as email marketing is fundamentally about mass email campaigns.

➡️ How to check: To assess your SMTP, consider using online checker tools such as the one offered by MxTool Box. It's always wise to ensure your SMTP is functioning optimally for the health of your email domain. 

Strong Redirect Setup  

By redirecting links in your email to your main site, you reinforce the connection between the email and your domain.This can help establish a positive email sender reputation over time, as consistent branding and traffic patterns indicate legitimate and trustworthy communication. Also, it enhances brand recognition and familiarity, provides a seamless user experience and increases engagement promotes consistency and transparency, making you stop asking, “Why are my emails going to spam?”

Contrary to this, if you include links in your email that direct recipients to unfamiliar or unrelated websites, it may raise suspicions of phishing or spoofing. This can trigger spam filters or cause recipients to mark your emails as spam.

➡️ What to do: Double-check whether all your domains and subdomains lead to the main website. While redirecting to the main site can be beneficial for email deliverability, it's important to ensure that your main site and landing pages are secure, mobile-friendly, and provide relevant and valuable content to the recipients. 

Review Your Domain Levels

In large organizations, every department or division may include a unique third-level domain that can act as a simple yet effective, way of identifying that particular department. Various third-level domain names are used to balance the load on sites with heavy traffic.

A third-level domain is the next highest level, following the second-level domain in the domain name hierarchy. It is the segment that is found directly to the left of the second-level domain. The third-level domain is often called a “subdomain”, and includes a third domain section in the URL.

➡️ What to do:  

Make sure you use trustworthy domains. Here’re recommendations from our tech team: 

  1. .com/ .io / .co — the most trustworthy domains (such domains are strongly associated with great email domain health)
  2. .net /.org — the domains with strong levels of trustworthiness
  3. All other domains are associated with less strong email domain health

Check Your Current Domain Reputation

Tools like Folderly help you quickly check your current domain reputation and assign an email deliverability score for your potential campaigns. You can get a quick overview of key issues with your domain and address the problems before they negatively affect your email domain's health. 

➡️ What to do: Read the full article on how to test email deliverability or just check email deliverability in a few clicks.


Bottom Line: It’s All About Comprehensive Approach

Checking the six critical components discussed in this article will give you a clear picture of your current email deliverability state. However, to ensure optimal deliverability and maintain a successful email marketing strategy, it is crucial to take a comprehensive approach to email domain health. 

While we discussed key building blocks, there are other important things to check, such as email list hygienespam trigger words, sending frequency, email compliance, and other crucial things to address that may help prevent email from going to spam.

And, to truly unlock the potential of your email campaigns, consider harnessing the expertise of professional email deliverability consulting services offered through dedicated customer success managers. With the guidance of customer success managers, you can navigate the intricate web of sender authentication, list hygiene, engagement metrics, and technical infrastructure management with ease. They will equip you with the tools and strategies to conquer deliverability challenges and optimize your email domain health. 



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