Using a custom email domain for sending your campaigns and automation emails is a top deliverability requirement. It helps improve deliverability and strengthen brand recognition.
This article will teach you how to automatically sign, verify, and use your sender custom domain in Omnisend.
New to email authentication? Learn about SPF, DKIM, and DMARC records.
Before You Begin
If you haven’t verified a custom sender domain in Omnisend, your emails will be sent using Omnisend’s shared domain by default. Read below on how to check your current domain setup.
Domain signing is free for all Omnisend users.
Identify your domain provider before you begin. Each provider has different instructions for adding DNS records. If you are unsure, use who.is and check the Registrar or Name Servers field.
Test emails always use Omnisend’s shared domain. You cannot assign a custom domain to a test email.
A custom domain doesn't guarantee better deliverability. You must warm up your domain after verification and follow deliverability best practices.
As the final step, make sure your verified domain or subdomainb is assigned to your Email Campaigns, Email Automations, and Double opt-in emails under Store settings → Domains → Domain usage.
💡 In Omnisend, you can also add and verify your custom SMS domain in order to use branded SMS short links.
Why Use a Custom Email Domain?
A custom domain for your email marketing might seem minor in the bigger marketing picture, but it's crucial.
1. Authenticate your emails
Domain signing authenticates your emails, helping Internet Service Providers (ISPs) trust the sender. This strengthens your sender reputation and increases your chances of landing in the primary inbox since mailbox providers factor domain reputation into delivery decisions.
2. Increase your brand awareness
A custom domain reinforces your brand identity and makes your emails more recognizable. Including your brand name in the sender domain helps you stand out from competitors and build trust with your audience.
A verified custom domain can also be assigned to double-opt-in emails, creating a consistent sender experience from the first subscription confirmation.
3. Improve email performance
In Omnisend, we recommend using separate subdomains for Campaigns and Automations. Root domains are often overloaded with other uses, which can hurt email performance. For better deliverability and clarity between message types:
Use your main domain for campaigns (e.g.
mybrand.com)Use a subdomain for automations (e.g.
news.mybrand.comoremail.mybrand.com)
This separation is considered best practice for managing promotional and transactional emails.
Check Your Current Domain Setup
To see whether you're using a shared or custom (dedicated) domain, go to Store settings → Domains.
You’ll see one of the following statuses:
No custom domain: The list is empty, and you're using Omnisend’s shared domain.
In progress: A domain has been added, but authentication is still ongoing.
Verification usually takes about 30 minutes, but DNS propagation can take up to 48 hours. While the status is In progress, wait for the verification check to complete and review your DNS records if needed.
Unverified: A domain has been added, but verification failed due to incorrect authentication setup.
Verified: Your custom domain has been successfully authenticated.
Set Up Your Custom Email Domain
Step 1. Go to Store settings → Domains.
Step 2. In order to sign your own domain, click + Add domain button.
Step 3. Choose the Email option for the domain type.
Step 4. Select your domain provider.
Omnisend will generate personalized instructions based on your domain provider. If you’re not sure who your provider is, select "I don't know" or search your domain name here to find out.
Step 5. Provide the exact domain (or sub-domain) you want to use for your Campaigns and/or Automation.
We recommend using a domain that matches your website, such as:
storename.cominfo.storename.comnews.storename.comemail.storename.com
⚠️ Important: If your sender domain is already connected to another Omnisend account or brand, or was previously authenticated through Mailgun, you may see a message that the domain is already connected elsewhere.
If you own the domain, the system will guide you through an ownership claim. Add the DNS record shown in Omnisend to your domain provider, then return to Omnisend and continue the verification steps.
Add SPF, DKIM, and DMARC Records
Step 1: Add Records to Your DNS Settings
Click on your domain name in Omnisend to view the SPF, DKIM, and DMARC records you need to add to your DNS provider's settings.
On the Domain setup page, you’ll see the records you need to add to your DNS provider’s settings, along with step-by-step instructions based on the domain provider you selected.
Important: For the DKIM record, you will be requested to enter the DKIM selector, which is the part before ._domainkey. However, it might be different for some domain providers; for example, GoDaddy requires a full DKIM selector, including ._domainkey, and the subdomain name as highlighted below:
You can find further instructions provided by the most popular DNS provider in our dedicated article. If you face any problems, we highly encourage you to follow our troubleshooting tips.
However, if you don't find the provided instructions helpful, reach out to your DNS provider for more detailed and personalized instructions. Remember that different DNS providers may have varying rules for adding these records.
Don't know who your DNS provider is? You can easily find it here.
Step 2: Verify Your Domain
Once you've added the required records to your DNS settings, return to Omnisend and click Finish verification to start the domain verification process.
You'll see a confirmation message letting you know your domain is being verified – Omnisend will email you once the status changes.
Step 3: Select Your Domain Usage
After clicking Finish verification, you can choose where to use this domain:
Select Email campaigns to automatically use this domain for all campaigns once verified.
Select Email automations to automatically update active automations to use the verified domain.
Select Double opt-in to automatically use the verified domain for double opt-in emails.
Click Continue.
All three options are pre-selected and recommended. Once verification completes, Omnisend automatically applies the domain to your selected areas – no manual assignment needed.
You can always go back and adjust which areas use your domain, or update your sender email address if you selected the wrong option during setup.
Step 4: Choose Your Sender Email Address
You'll see two options:
Use one address for campaigns and automations (recommended) – Enter a single sender email (e.g., if your domain is
store.com, use a sender address like[email protected])Use different addresses for campaigns and automations – Specify separate sender emails for each
Enter your sender email address and click Confirm & finish.
Your verification status will update to In progress, and Omnisend will begin checking your DNS records on the backend. You’ll receive an email notification once the process is complete or if there’s an issue.
Step 5: Wait for Verification
Domain verification typically takes around 30 minutes, but in some cases, it may take up to 48 hours. This is because DNS changes can take up to 24 hours to fully propagate, which delays verification.
While waiting, you can manually check if your SPF and DKIM records were added correctly using this tool. Enter your domain name, and the tool will show whether your records are properly configured or if there are any errors.
Step 6: Check Verification Status
After verifying your records, the system will label your domain as either Verified or Unverified. If verification fails, you’ll see which specific records (SPF, DKIM, or DMARC) caused the issue, along with the reason for the failure and steps to troubleshoot it.
Note: If any of the required records fail to validate, the domain cannot be verified, and you won’t be able to select it for sending emails.
Step 7: Verify the Domain usage
After verification completes, check that your domain is assigned correctly.
If you selected Email Campaigns, Email Automations, and Double opt-in in Step 3, the domain is automatically applied – no further action needed. Your campaigns, automations, and double opt-in emails will use the new domain immediately.
If you skipped domain selection during verification, you'll need to manually assign the domain. Go to Store settings → Domains → Domain usage, and select your verified domain from the dropdown for:
Email Campaigns
Email Automations
Double opt-in
Make sure you also use a branded sender email address so recipients recognize your messages.
⚠️ Important: After your domain is verified and assigned, warm up your domain before sending high-volume campaigns. Skipping this can harm deliverability.
Troubleshooting Authentication Issues
If your domain fails to verify, Omnisend will prompt you to fix the setup from several areas in your account, including:
Campaign setup;
Automation setup;
Store settings;
A top banner in your account.
To proceed with authenticating your domain, click 'Fix setup' from any of the locations mentioned above in your account.
You’ll be redirected to the Domain setup page, where you can see which of the three records (SPF, DKIM, or DMARC) needs to be fixed, along with step-by-step instructions.
Any record marked Not Found needs to be added to your DNS settings. Once you've updated your DNS, click Check verification manually in the bottom-right corner of the page.
Note: DNS changes may take up to 48 hours to propagate. If your new records aren’t verified right away, check back later and try again.
Most common errors and how to fix them:
SPF Record Errors
SPF records are not found
If you're adding an SPF record for a subdomain, make sure to include only the subdomain in the Name field, not the full domain.
In some DNS setups, you may also need to use the
@symbol instead of the domain name. In DNS zones,@represents the root domain, so using it may be sufficient depending on your provider.
Duplicate SPF TXT Records
A domain can only have one SPF record. However, it’s common to see multiple records, especially when using multiple email service providers, each instructing you to add their own. To fix this, you need to merge all SPF entries into a single record. For example:
Incorrect – Two separate SPF records:
“v=spf1 include:_spf.google.com ~all”“v=spf1 include:mailgun.org ~all”Correct – Combined into one SPF record:
“v=spf1 include:mailgun.org include:_spf.google.com ~all”
Use the SPF syntax validator to check the combined record.
💬 Learn more: Troubleshoot SPF Errors.
DKIM Record Errors
Something is wrong with the DKIM records
If you're using GoDaddy and can't see your DKIM record when checking setup, double-check the Name field in your DNS. Omnisend provides a fully-qualified domain name (e.g.,
something._domainkey.yourdomain.com), but in GoDaddy, you should not include the domain name.Example: If given
something._domainkey.yourdomain.com, enter onlysomething._domainkeyin the "Name" field.
DMARC Record Errors
Check if the "Name" value is set to
_dmarc.yourdomain.com.If verification issues persist, try changing the "Name" value to just
_dmarc.
Records Added at the Wrong Domain Level
Confirm whether you added records for your root domain (yourdomain.com) or a subdomain (email.yourdomain.com). The records must match exactly the domain entered in Step 5 of the setup process.
FAQ
How will the recipients see the email sent from my store after I sign a custom domain?
When you send emails via Omnisend's shared domain, recipients see our shared domain in the sender field.
Once you sign your custom domain, recipients will see your store's domain. This improves deliverability and promotes your brand.
If your sender domain and sender email address use the same domain (e.g., sender domain basicpiece.com and Sender email newsletter@basicpiece.com), Gmail will display the sender info as follows:
What DMARC record should I use?
Omnisend provides a basic DMARC record during domain authentication. For a more advanced record, use the DMARCian setup wizard.
How long does domain verification take?
DNS verification typically takes 30 minutes, but can take up to 24–48 hours depending on your DNS provider. Omnisend will email you once verification is complete. If it's been longer than 48 hours, check for typos in your DNS records or contact your DNS provider to confirm propagation.
Why is my domain still showing "Not Found" or "Couldn't verify" after I added the records?
This usually means DNS records haven't propagated yet (can take up to 48 hours), or there's a typo in the Name or Value fields. Double-check your records match exactly what Omnisend shows, and use MXToolbox or whatsmydns.net to confirm records are visible. If records are correct and it's been 48+ hours, contact your DNS provider.
Have other questions? Feel free to contact our 24/7 Support Team via in-app chat or [email protected].