This resource uses Mailchimp as an example, but can be applied to other services such as EmailOctopus.

If you are not sure what a domain is, check out our 'Demystifying domains' resource.

Why this matters 

When you send emails or newsletters using tools like Mailchimp, EmailOctopus or similar platforms, the message does not come directly from your own email system. It is sent through a third-party service.

Because of this, email providers receiving your email (such as Gmail, Outlook and Yahoo) need to check two things: 

  1. You really own the domain you are using 
  2. The service you are using is allowed to send emails on your behalf 

Mailchimp is very clear on this: 

  • Verification confirms access to your email address 
  • Authentication proves you are a legitimate sender and improves delivery

Without authentication: 

  • Emails are more likely to go to spam 
  • May not be delivered at all 
  • May appear as coming “via” another domain 

Modern email systems rely heavily on this validation. Authentication is no longer optional for reliable delivery.

example of error message for no authentication

This is an example error message your recipient might receive if you don’t authenticate your domain for your newletter system (e.g. Mailchimp).

The difference between verification and authentication

This distinction is important.

Domain verification 

This is a simple check. 

  1. Mailchimp sends a verification email 
  2. You confirm that you have access to that inbox 
What it does:

✔ Allows you to send emails 

What it does NOT do:

✘ Improve deliverability 

Mailchimp specifically notes that verification alone does not affect inbox delivery.

Domain authentication

This is the key step. 

It involves adding records to your domain (DNS): 

  • SPF – confirms who is allowed to send 
  • DKIM – confirms the email has not been altered 
  • DMARC – tells providers what to do if checks fail 

Together, these act like a digital ID system for your emails.

What it does:

✔ Improves inbox delivery 
✔ Builds trust with email providers 
✔ Prevents spoofing (people pretending to be you) 

How the process works (in simple terms)

  1. You add your domain in Mailchimp
  2. You verify access to an email address
  3. Mailchimp gives you DNS records
  4. You add these to your DNS via your domain provider
  5. Mailchimp checks them and confirms authentication

That is it. It is a one-off setup taking around 10-15 minutes.

Example walkthrough using real screenshots

Below is a real example showing each step.

Step 1: Go to your domains area and add your domain

In Mailchimp, go to:

  • Account
  • Domains

You will see your domain listed and a button to begin setup.

What to look for:
  • Your domain name, as an example we are using kewvillagemarket.org
  • A status such as Needs authentication
  • A button to start the process

domain authentication step 1

Step 2: Verify that you own the domain

Mailchimp will ask you to enter an email address linked to your domain.

What you do here:
  • Enter an address such as info@yourdomain.org
  • Click Send Verification Email
  • Open the email and confirm

This step matters as it proves you control the domain before you are allowed to send.

domain authentication step 2

Step 3: Start authentication and get your DNS records

Once verified, Mailchimp shows instructions titled something like: “Add records to your DNS settings”.

This is the most important screen.

What you will see:
  • CNAME records (for DKIM)
  • A TXT record (for DMARC)

For example:
•    CNAME → k2._domainkey... → dkim2.mcsv.net
•    CNAME → k3._domainkey... → dkim3.mcsv.net
•    TXT → _dmarc → v=DMARC1; p=none;

What to do:
  • Copy these exactly.

domain authentication step 3

Step 4: Open your domain provider and access DNS settings

Now go to the system where your domain is managed (typically, 123Reg, GoDaddy, IONOS, 20i etc.).

In our example (20i), this is:

  • Domains
  • Manage DNS
What to look for:
  • DNS settings or DNS management
  • A list of existing records

domain authentication step 4.1

domain authentication step 4.2

Step 5: Add the DNS records

This is where many people get unsure, but it is straightforward.

For each record from Mailchimp:

  • Select the correct type (CNAME or TXT)
  • Paste the Name
  • Paste the Value
  • Save
Important points:
  • Do not delete existing records
  • Copy values exactly
  • Small errors/typos will prevent verification

The screenshot below shows:

  • Some existing records (A, MX, email settings)
  • New Mailchimp CNAME records being added

domain authentication step 5

Step 6: Return to Mailchimp and complete authentication

After adding your records:

  • Go back to Mailchimp
  • Click to validate or continue

If everything is correct, you will see confirmation.

Final result from example:

“Your domain is authenticated! Your emails will now flow freely into your customer’s inboxes.”

domain authentication step 6

Common issues
  • DNS changes can take time (often minutes, but sometimes longer)
  • Records not copied exactly
  • Adding them in the wrong DNS provider (you need to add them where your Domain is controlled – the nameserver settings will confirm this)

If it fails at first, wait and try again.

 

Download the pdf step-by-step guide here

Final takeaway

  • Verification lets you send emails.
  • Authentication makes sure they arrive.

Mailchimp and other platforms all follow the same principle.

Once this is set up, it quietly works in the background and makes a noticeable difference to whether your emails reach people.

References

“About Email Authentication.” Mailchimp, https://mailchimp.com/help/about-email-authentication/.

“SPF, DKIM, and DMARC Explained.” Mailchimp, https://mailchimp.com/solutions/spf-dkim-dmarc/.