Suped

How does a dedicated sending domain in Klaviyo affect Google Postmaster Tools data?

Michael Ko profile picture
Michael Ko
Co-founder & CEO, Suped
Published 19 Jun 2025
Updated 16 Aug 2025
8 min read
When you send emails through a platform like klaviyo.com logoKlaviyo, a crucial aspect of your email deliverability and sender reputation is the domain from which your emails appear to originate. Many users start on a shared sending domain, which can lead to emails displaying a "via klaviyomail.com" message next to their sender address. This configuration has significant implications for how you can monitor your email performance, particularly through Google Postmaster Tools.The core question many marketers ask is whether they can gather meaningful insights from Google Postmaster Tools without having their own dedicated sending domain. The short answer is largely no. Google Postmaster Tools, by design, provides data based on the authenticated domain that sends the emails, meaning the domain that passes authentication checks like SPF, DKIM, and DMARC. If your emails are authenticated by Klaviyo's shared domain, the data in Postmaster Tools will reflect Klaviyo's aggregate sending reputation, not your brand's specific performance.

The necessity of a dedicated sending domain

A dedicated sending domain is paramount for establishing and maintaining your brand's unique email sending reputation. When you use a shared domain, your email's reputation is intertwined with every other sender using that same domain. This means that if another user on the shared domain engages in poor sending practices, it can negatively impact your deliverability, even if your campaigns are exemplary. Moving to a dedicated (or branded) sending domain gives you granular control and ensures that your sending practices directly influence your reputation.
Beyond reputation, a dedicated sending domain is essential for proper email authentication, including SPF, DKIM, and DMARC. When you configure a dedicated sending domain, you are setting up these authentication protocols for your own domain, allowing mailbox providers like google.com logoGoogle and Yahoo to verify that your emails are legitimate and truly come from your brand. Without this, your emails might appear less trustworthy, increasing the likelihood of landing in spam folders.

Why dedicate your domain?

  1. Full control: Your sender reputation is solely tied to your sending practices, not shared with other users.
  2. Brand consistency: Emails appear directly from your domain, enhancing trust and recognition.
  3. Postmaster Tools data: Enables access to specific, actionable data about your domain's performance.
Klaviyo's documentation provides a comprehensive guide on how to set up a dedicated sending domain within their platform, which is a critical first step.
Ultimately, a dedicated sending domain is not just a best practice, it is a foundational element for serious email marketers to ensure optimal deliverability and reputation management. It's the only way to genuinely leverage tools like Google Postmaster Tools for your specific brand's sending health.

Shared domains and Postmaster Tools visibility

When you use Klaviyo's shared sending domain, such as klaviyomail.com, your emails are technically signed and authenticated by their domain. This means that any data reported in Google Postmaster Tools, such as spam rates or domain reputation, pertains to klaviyomail.com itself, not your brand's domain. You would not be able to add your own domain to Google Postmaster Tools and expect to see relevant data, as your emails aren't being authenticated by it.
This lack of direct data can be a major hurdle for understanding and improving your email program. Without your own dedicated domain for authentication, you lose the ability to track critical metrics like spam complaint rates, domain reputation, or delivery errors that are specific to your sending volume and audience engagement. You're essentially flying blind in terms of your sender health with mail.google.com logoGmail recipients.

Shared domain

  1. Authentication: Emails are authenticated by klaviyo.com logoKlaviyo's shared domain, such as klaviyomail.com.
  2. Postmaster Tools data: No specific data for your brand's domain. Any data would reflect the aggregated performance of the shared domain.
  3. Reputation control: Your sender reputation is influenced by all other senders on the shared domain.

Dedicated domain

  1. Authentication: Emails are authenticated by your own domain with SPF, DKIM, and DMARC records.
  2. Postmaster Tools data: Provides detailed, actionable insights for your specific domain's email performance.
  3. Reputation control: You have full control over your sender reputation, which is built on your sending practices alone.
The inability to monitor your own domain's reputation on Google Postmaster Tools leaves you vulnerable to unforeseen deliverability issues. You won't know if your emails are consistently landing in spam for Gmail users until it significantly impacts your campaign performance. This is why transitioning to a dedicated sending domain is not merely a suggestion, but a requirement for robust deliverability monitoring.

Setting up your dedicated domain for Postmaster Tools

To unlock the full potential of Google Postmaster Tools for your Klaviyo emails, the critical step is setting up a dedicated sending domain. This process involves configuring specific DNS records (Domain Name System records) that tell mailbox providers that you authorize klaviyo.com logoKlaviyo to send emails on behalf of your domain. The primary records you'll need to set up are SPF, DKIM, and DMARC.
Once your dedicated sending domain is configured within Klaviyo and the corresponding DNS records are published in your domain's DNS settings, your emails will be signed by your domain. This alignment is what enables postmaster.google.com logoGoogle Postmaster Tools to collect and display data specific to your domain's sending activity. It’s important to note that you may need to reach out to Klaviyo support for assistance with custom DKIM signing if not readily available in your account settings.
Example DNS records for a dedicated sending domain in Klaviyo:DNS
TXT yourdomain.com v=spf1 include:spf.klaviyomail.com ~all CNAME k1._domainkey.yourdomain.com k1.domainkey.klaviyomail.com CNAME k2._domainkey.yourdomain.com k2.domainkey.klaviyomail.com TXT _dmarc.yourdomain.com v=DMARC1; p=none; rua=mailto:reports@yourdomain.com
Once these DNS records are in place, particularly the DKIM records that enable your domain to sign the emails, you can then add your domain to Google Postmaster Tools and verify ownership. This crucial step allows Google to associate the email traffic with your specific domain and begin populating your dashboard with valuable data. Learning how to understand SPF, DKIM, and DMARC is key to effective deliverability.

Interpreting your data in Google Postmaster Tools

Once your dedicated sending domain is properly set up in Klaviyo and verified in Google Postmaster Tools, you'll start to see a wealth of data that was previously unavailable. This includes your Domain Reputation, IP Reputation, Spam Rate, Feedback Loop data, and Authentication details. These metrics are crucial for proactive deliverability management. For instance, the difference between IP and domain reputation becomes clear, as you'll see reports specific to your domain.
The support.google.com logoGoogle Email sender guidelines emphasize the importance of monitoring these metrics to ensure good standing with Gmail and Google Workspace recipients. Having your own dedicated domain for authentication means you're seeing data specific to your actual email stream, not a shared pool. This granular insight allows you to pinpoint issues quickly and take corrective action, whether it's related to content, audience engagement, or list hygiene. For example, understanding how long it takes for new subdomains to report data can help manage expectations during domain warming.

Report Category

Data Provided with Dedicated Domain

Data without Dedicated Domain

Spam Rate
Accurate spam complaint rates for your specific sending domain.
No specific data, only aggregate rates for Klaviyo's shared domain.
Domain Reputation
Reputation score (Bad, Low, Medium, High) based solely on your sending practices.
No specific data for your brand. Reputation tied to the shared domain.
Authentication
Visibility into your SPF, DKIM, and DMARC pass/fail rates.
Authentication details for Klaviyo's domain, not your own.
Delivery Errors
Insight into specific errors like DNS issues or rate limiting for your domain.
No specific error reporting for your brand's sending.
By actively monitoring these reports, you can ensure your emails consistently reach the inbox and troubleshoot any deliverability issues quickly. It allows you to respond to changes in your sender reputation, whether due to content, audience engagement, or even blacklist (or blocklist) issues, directly from your domain's perspective. For a more detailed look into these metrics, consult our ultimate guide to Google Postmaster Tools.

Views from the trenches

Best practices
Always set up a dedicated sending domain in your ESP for brand control and deliverability insight.
Regularly monitor your Google Postmaster Tools dashboard once your dedicated domain is configured.
Ensure SPF, DKIM, and DMARC are correctly set up and aligned for your dedicated domain.
Use a subdomain for marketing emails to protect your primary brand domain's reputation.
Gradually increase email sending volume when using a new dedicated domain to build a positive reputation.
Common pitfalls
Relying on shared sending domains for authentication, which prevents access to specific brand data.
Failing to set up custom DKIM signing for your dedicated domain.
Not adding your dedicated sending domain to Google Postmaster Tools for verification.
Ignoring Google Postmaster Tools data, leading to undetected deliverability issues.
Abruptly increasing sending volume on a new dedicated domain, risking reputation damage.
Expert tips
Configure a dedicated sending domain through your ESP's support if direct options are unclear.
Review Google's sender guidelines annually as requirements for bulk senders evolve.
Implement a DMARC policy with reporting to gain comprehensive insights into email authentication.
Segment your email sending by subdomain (e.g., transactional vs. marketing) for better reputation isolation.
Automate monitoring of your sender reputation and authentication status for proactive issue resolution.
Marketer view
Marketer from Email Geeks says a brand currently using a shared Klaviyo sending domain cannot get insights from Google Postmaster Tools, as it is a requirement to have a dedicated sending domain.
2023-06-19 - Email Geeks
Marketer view
Marketer from Email Geeks says that users need to sign custom DKIM from Klaviyo to resolve the issue of emails showing a 'via' message.
2023-06-19 - Email Geeks

Taking control of your deliverability

Adopting a dedicated sending domain in klaviyo.com logoKlaviyo is a fundamental step toward mastering your email deliverability and leveraging Google Postmaster Tools. Without it, you are reliant on shared reputation and lack the direct insights necessary to diagnose and resolve deliverability issues specific to your brand. This move provides your brand with direct control over its email reputation and ensures that the valuable data from Postmaster Tools is truly reflective of your sending performance.
The transition to a dedicated sending domain, complete with proper SPF, DKIM, and DMARC setup, allows for precise monitoring of your email health, helping you avoid spam folders and maintain a strong sender reputation. It's an investment in your long-term email marketing success, empowering you with the data needed to make informed decisions and build trust with your subscribers.

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