Email Infrastructure and Service Providers

The Beginner’s Guide to Domain Use in Email Marketing

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Imagine you’re walking down the soda aisle at the supermarket. As you search for a tasty beverage, you see a familiar brown soda bottle with a red plastic label.  

Without thinking, you stop and grab it. Boom! That’s the power of branding. 

A company’s brand is its most valuable asset. Just look at Apple—Apple’s brand value is estimated at $241 billion.

And a key part of any successful brand strategy is a company’s domain name.  

Your company’s domain name helps people recognize your website and email address, and serves as a representation of your company, both online and in the inbox. 

Most brands have websites that people can visit to make purchases and find more information about their business. Most also communicate directly with prospects and clients via email. A domain name that people can read and remember is the all-important link between the two channels.  

Since this area can be technical and somewhat confusing, let’s dive into some important considerations for email marketers formulating a domain strategy—including which domain type to choose, how to use your domain to reinforce your brand, and how to protect your domain from cyber threats. 

What is a domain name? 

In plain English, we’ll define “domain” (short for domain name) as “the bit after the @ sign in the email address.”  

We’ll use our own website as an example. “” is the domain for the address “[email protected]”.  

A domain name is a company’s web address—or the text that web users type into a browser to reach a particular website. 

When looking at a subdomain, you’ll see a different setup with a few more dots. Take, for example, “” Looking at this web address, we know “everest” is a subdomain of the parent domain “” So, Validity has a domain named “” and a subdomain named “” 

A subdomain lets companies organize their websites into logical parts. Using a subdomain, companies can separate specific content—like blogs or online stores—from the rest of the website.  

Domain and subdomain names will appear in the “From” address of email messages. 

Senders can use either a domain or a subdomain to send emails. It’s important to remember that the email subdomain has a separate sender reputation from that of the parent domain. 

Sending emails from your company’s website domain 

There are more than 360 million domain names in use right now—and thousands more are registered each day.  

If you’re planning to launch a new website, choose wisely. Picking a name for your company is tough, and it’s always a good idea to check if the domain you want has already been taken. (For help choosing a domain name, use a free domain name generator.) 

To keep your branding consistent, the domain used in an email message’s “From” address should be the same as the website domain name, or at least a subdomain of it.  

An email service provider (ESP) will typically be contracted to help you send marketing campaigns from your domain or choose a platform that lets you configure a subdomain to send messages on behalf of your brand.  

Avoid registering a new domain just to send email. This is (unfortunately) a common practice, and it’s never a good idea. 

For example, “” would be a cousin domain (or look-alike domain) of “”They look similar but could have been registered by two different organizations.  

Using cousin domains can confuse subscribers and employees.  

Cousin domains, especially if used for one-off mailings, can look like phishing campaigns. After all, this is exactly what spammers and phishers do: spoof a domain name by changing it just enough to confuse readers. 

  As a result, cousin domains can lead to spikes in spam complaints and emails being blocked by mailbox providers. 

Email marketing, branding, and domain use 

Messages sent by a company should be easily recognizable when they appear in an inbox. Additionally, the elements within the email should reflect the sender’s brand, including the logo in the email header, the color scheme, and the tone of the copy. 

As we’ve covered, domain name is another important part of reinforcing your company’s brand.  

Email subscribers, mailbox administrators, and filtering algorithms will rely on the domain portion of the “From” address to know more about the sender.  

Making it difficult for subscribers to recall or find information about the brand that sent the message typically leads to frustration, unsubscribes, spam complaints, or reports of phishing scams.  

To avoid these negative outcomes, it’s crucial that all parties are able to: 

  • See your website when pasting the domain into the browser’s address bar 
  • Recall where they signed up to get your messages 
  • Get basic information about your business  
  • Contact support or a data protection officer (DPO) if needed 
  • Get a response from a real person if they send an email to [email protected] or [email protected] 

Ensure optimal email deliverability 

Your domain can play a critical role in dictating your email deliverability—your ability to reach the inbox as opposed to being blocked or labeled as spam. 

To maintain good deliverability, senders need to take responsibility for what they send. This means sending content that people want to receive, from a domain and IP address (or addresses) that has a good reputation with mailbox providers.  

Mailbox providers use domain name and history as a basis for making delivery decisions. 

In other words, these domains or IPs must be known for following established best practices and have no record of spam-like behavior. 

If you currently send email marketing campaigns, your domain already has a sender reputation. You can check your sender reputation using resources like Sender Score, Google Postmaster Tools, and Microsoft SNDS. 

Know that it’s far easier to improve and maintain your reputation than it is to build a new one from scratch.  

Some senders will try to build a new sender reputation (or erase a poor one) by simply registering a new domain. Generally speaking, this isn’t a good idea. 

These senders usually end up transferring their problematic email strategies to a new domain. So, focus on improving your sending practices instead. 

Protect your domain from cyber threats 

Mailbox providers must ensure their email servers are running and capable of receiving messages.  

Unfortunately, they must also deal with spam, phishing attacks, and malware. A whopping 75 percent of cyberattacks start with email. These are often widespread attacks that require low-cost infrastructure and can be operated and automated by few people.

These spammers have no concern about sender reputation and a complete disregard for data privacy—a completely different setup from how serious businesses run their email marketing programs. 

What do reputable senders do differently? Glad you asked.  

Throughout the years, email authentication protocols have been created to help confirm and verify the identity of email senders—and to help senders protect their domains from phishing and spoofing attacks. 

To protect your domain, ensure that:  

  • Your sending domain has an SPF record set to “-all” or “~all” 
  • Your messages are sent with a DKIM signature with a 1028-bits key or above 
  • You have a DMARC record and you monitor the reports sent by mailbox providers to the email addresses that are set up in “rua=” and “rua=” tags

Personally, I like to use Everest to monitor DMARC reports and other authentication protocols.

These are the building blocks. From there, it’s up to senders to do the heavy lifting to protect their domains from bad actors. 


Let’s recap what we’ve learned. Email messages include the organization’s domain name, which is the name we remember when we visit a website, like or 

In email, the domain is a part of the “From” address. Some senders will use a subdomain instead, like 

A sender’s domain strategy can impact their brand identity, email deliverability, and cybersecurity.

Additionally, domain is a crucial aspect of sender reputation.

To learn other components of building and maintaining a strong sender reputation, download the All-in-One Sender Reputation Toolkit.