X-Google-DKIM-Signature: How to Add It?
Seeing X-Google-DKIM-Signature in your email headers and not sure what it means?
Most people ignore it, but that line tells you one thing: your domain isn’t doing its job
It appears when Gmail steps in because your domain’s DKIM failed. Which means your emails are at risk of not being trusted.
This blog is a complete breakdown of:
- What the X-Google-DKIM-Signature means
- Why Gmail adds it to your emails
- How to fix it
- And how to set up DKIM properly in Google Workspace
And, if you're tired of handling DNS records or want a quicker way to fix authentication issues, I’ll also show you how Primeforge makes it much easier.
What Is X-Google-DKIM-Signature in Gmail?
X-Google-DKIM-Signature is a header added by Gmail after your email is delivered.
It acts like a backup DKIM check that Gmail performs on its own.
Unlike your standard DKIM-Signature, which is applied by your domain, this one is created by Gmail to verify message integrity using its own keys.
It only appears when:
- Your domain’s DKIM fails or isn’t present
- Gmail still wants to protect the message and prevent tampering
This means your domain didn’t pass DKIM validation, and Gmail had to take over the authentication process.
Why Gmail Adds X-Google-DKIM-Signature to Emails?
Gmail adds the X-Google-DKIM-Signature when your own DKIM is either missing, misconfigured, or fails validation.
This header is Gmail’s way of verifying your message after delivery, using its internal security checks.
It’s part of Gmail’s effort to stop email tampering, phishing, or spam.
In short, it appears because:
- Your domain didn’t sign the email properly with DKIM
- Gmail still wants to keep the message secure
- It uses its own DKIM keys as a fallback
So, even if your DKIM fails, Gmail still adds this signature to keep things intact.
But here’s the catch: while it looks like your email is authenticated, your domain’s trust is still at risk.
If this header keeps showing up, you need to fix your DKIM setup quickly, especially if you care about inbox placement and deliverability.
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X-Google-DKIM vs Standard DKIM-Signature: What’s the Difference?
Both X-Google-DKIM and the standard DKIM-Signature confirm email authenticity, but they serve different roles and come from different sources.
Here’s a clear comparison to understand their purpose and impact:
Here, your domain’s standard DKIM is the primary method to prove your email is legitimate.
If it fails, Gmail uses its X-Google-DKIM to maintain message security.
So, if you want to ensure full control over your email reputation and deliverability, focus on setting up and maintaining a strong, valid standard DKIM.
How To Fix X-Google-DKIM-Signature Errors in Gmail
If you’re seeing X-Google-DKIM-Signature often, it likely means your DKIM isn’t set up properly or it’s broken.
That puts your domain trust and inbox placement at risk.
⛔Here’s what usually causes the issue:
- DKIM is not enabled in Google Admin
- Selector mismatch between your domain and Google’s DNS records
- Broken or missing TXT record in your DNS
- Propagation delays after DNS updates
- Gmail's fallback kicks in when your domain fails DKIM
➡️ To fix it, follow these steps:
- Log in to Google Admin Console
- Go to: Apps > Gmail > Authenticate Email
- Check if DKIM is turned on
- Verify the selector name and domain match
- Use MXToolbox or Gmail header parser to confirm it’s working
Once DKIM is properly set, Gmail stops adding X-Google-DKIM.
And your emails start passing with your own domain’s signature.
How To Set Up DKIM in Google Workspace (Step-by-Step)
If your emails keep failing DKIM, you need to set it up inside your Google Admin Console and domain DNS.
Here’s how to do it in three steps:
Step 1: Generate Your DKIM Key in Google Admin
You must be signed in as a super admin.
- Go to Google Admin Console
- Navigate to: Apps > Google Workspace > Gmail
- Click Authenticate email
- Choose your domain
- Click Generate New Record
Use the 2048-bit key if supported, and keep the default prefix Google.
Google will now generate two things:
- DNS Hostname (goes in the TXT record name)
- TXT record value (your public DKIM key)
Important: Do not click "Start Authentication" yet. Wait until you update the DNS.
Step 2: Add the DKIM Key to Your Domain DNS
Now, head to your domain registrar (like GoDaddy, Namecheap, etc.).
Add a TXT record using the values from Step 1.
Save the record and wait for propagation. It can take up to 48 hours.
Step 3: Turn On & Verify DKIM
Once DNS is updated:
- Return to Google Admin Console > Gmail > Authenticate Email
- Click Start Authentication
To confirm it’s working:
- Send an email to a Gmail inbox (not your own)
- Click Show Original
- Look for DKIM=pass in the Authentication-Results section
That’s it. Your domain now signs every outgoing email with a verified DKIM signature.
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Still Failing? Set Up SPF and DMARC Too
DKIM alone isn’t enough. To fully authenticate your emails, you also need to set up SPF and DMARC.
Here’s what each of them means:
- SPF (Sender Policy Framework): Tells receiving servers which IPs or services are allowed to send emails on your behalf. It prevents spammers from faking your domain.
- DMARC (Domain-based Message Authentication, Reporting & Conformance): Tells email providers what to do if SPF or DKIM fails, and gives you reports on who’s trying to spoof your domain.
If either of these is missing or misconfigured, your emails can still land in spam. So, here’s how you can set them up:
Step 1: Configure SPF
- Sign in to your DNS provider
- Create or edit a TXT record
- For Host, enter: @ or your root domain
- For Value, paste:
v=spf1 include:_spf.google.com ~all
- Save the record and wait up to 1 hour for configuration.
Step 2: Configure DMARC
- In your DNS dashboard, create a TXT record
- For Host, enter: _dmarc
- For Value, paste:
v=DMARC1; p=quarantine; rua=mailto:reports@yourdomain.com; ruf=mailto:forensics@yourdomain.com; pct=100 - Save and allow up to 1 hour for changes to take effect
Once done, verify both using:
- MXToolbox SPF Lookup
- Free DMARC analyzers (like Postmark or Dmarcian)
And when SPF, DKIM, and DMARC are all set up correctly, your domain earns trust, which then helps your emails stay out of spam.
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Primeforge: One-Click DKIM Setup for Google Workspace
If you're manually setting up SPF, DMARC, and DKIM, it’s a long, error-prone process.
From generating keys to editing DNS to verifying, it can be like a headache.
This is how Primeforge gives you control, automation, and visibility, even if you're managing 10+ domains or inboxes.
Primeforge is a cold email infrastructure platform built to handle all the backend complexity for outbound email. It helps you stay compliant, deliverable, and trusted at scale.
Instead of logging into DNS dashboards, generating keys, or waiting hours for propagation, Primeforge handles everything automatically and securely.
And, here’s how Primeforge can help you:
- Auto-setup SPF, DKIM, and DMARC without touching DNS
- Monitor inbox health across multiple domains in real-time
- Rotate inboxes automatically to spread volume safely
- Run built-in warm-up and throttling to protect domain reputation
- A central control panel to manage everything from one dashboard
How to Set Up DKIM in Google Workspace Using Primeforge
Setting up DKIM in Google Workspace with Primeforge takes less than 2 minutes. Here's how:
- Connect your domain and Gmail inbox to Primeforge
- Select "Auto Setup DKIM."
- Primeforge will generate the DKIM record
- It auto-publishes it to your DNS (Cloudflare, Google Domains, GoDaddy supported)
- Click "Start Authentication" from Primeforge’s dashboard
That’s it. DKIM is now live and verifiable
You don’t need to copy keys, wait 72 hours, or worry about record formatting.
This is how Primeforge gives you the control, automation, and visibility to manage DKIM, SPF, and DMARC all without the stress of doing it manually.
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Final Thoughts
If your emails keep showing X-Google-DKIM-Signature, it usually means your domain’s DKIM isn’t set up or working correctly.
And this damages your sender's reputation quickly.
Without proper DKIM setup, Gmail steps in to secure your emails, but relying on Gmail’s fallback solution can seriously impact your inbox placement.
So, to avoid this, here’s what you should always do:
- Set up DKIM correctly in your DNS records.
- Regularly verify DKIM status using MXToolbox.
- Align SPF and DMARC to authenticate fully.
- Monitor your email headers frequently.
- Fix any DNS issues as soon as they appear.
And, if you don’t want the headache of manually setting up DKIM, SPF, and DMARC, it’s better to use Primeforge, which automates it all instantly.
To start using Primeforge and ensure your emails consistently reach inboxes instead of spam, set it up once and let it handle authentication permanently.