How to Stop Spammers from Sending Emails From Your Domain
To stop spammers from sending emails that look like they came from your domain, you must implement a strict DMARC policy. By adding a DMARC TXT record to your DNS and setting the policy to "p=reject", you instruct global email providers like Gmail to automatically block and delete any spoofed emails pretending to be you.
What Is Domain Spoofing?
Domain spoofing is when attackers forge the "From" address on emails to make them appear sent from your domain. The emails never touch your servers, spammers simply type your address into their sending software.
How it works:
- Attacker sets up a mail server anywhere in the world
- They configure emails to show [email protected] as the sender
- Recipients see your domain, trust it, and fall victim to phishing
Without authentication protocols, email servers have no way to verify whether yourdomain.com actually authorized that message. Anyone can claim to be you.
This isn't a breach of your systems, it's exploitation of email's fundamental design flaw.
Why It Matters: Reputation and Liability
Domain spoofing destroys trust and deliverability:
Client phishing: Attackers send fake invoices using your identity. Clients get scammed; your brand takes blame.
Blacklisting: Spoofed emails reported as spam damage your reputation. Legitimate emails start landing in spam folders.
Legal exposure: If your domain is used in fraud, you face questions even as the victim.
Spoofing can permanently damage a sender reputation built over years.
Decision Framework: The 3 DMARC Policies
Policy | What Happens | Best For |
p=none | Monitor only, no action taken | Initial testing phase |
p=quarantine | Failed emails go to spam folder | Transition period |
p=reject | Failed emails blocked entirely | Maximum protection |
p=none: Emails deliver regardless of authentication. You receive reports showing senders. Use first.
p=quarantine: Suspicious emails land in spam. Moderate protection during transition.
p=reject: The ultimate cure. Receiving servers delete unauthenticated emails entirely.
Start with p=none, verify legitimate sources pass, then escalate to p=reject.
Implementation Steps
Step 1: Verify SPF Record Exists SPF tells servers which IPs can send for your domain. Confirm you have a TXT record like: v=spf1 include:_spf.google.com ~all
Step 2: Verify DKIM Is Configured DKIM adds cryptographic signatures to outgoing emails. Your email provider (Google Workspace, Microsoft 365, Titan Mail) provides DKIM keys to add as TXT records.
Step 3: Add DMARC TXT Record In NameSilo DNS Manager, add a TXT record:
- Host: _dmarc
- Value: v=DMARC1; p=none; rua=mailto:[email protected]
Step 4: Monitor Reports DMARC sends aggregate reports to your specified email. Review for 2-4 weeks to identify all legitimate sending sources.
Step 5: Escalate to Reject Once confident all legitimate emails pass, update to: v=DMARC1; p=reject; rua=mailto:[email protected]
Spoofed emails are now blocked globally.
Common Mistakes
Jumping straight to reject: If your CRM or newsletter tool isn't authenticated, p=reject blocks your own emails. Start with p=none.
Forgetting third-party senders: Marketing platforms and helpdesk software send as your domain. Each needs SPF/DKIM alignment.
No monitoring email: Without rua= reports, you're blind. Set up a dedicated address.
Ignoring DKIM: SPF alone isn't enough. DMARC needs SPF or DKIM alignment, ideally both.
What This Means for You
Add DMARC records in NameSilo's DNS Manager. Navigate to your domain, click the blue globe icon 🌎, and add a TXT record for _dmarc.
For complete email solutions including professional addresses at your domain, explore NameSilo Email.
Stop spammers from hijacking your identity. Implement DMARC today.
Frequently Asked Questions
How are spammers using my domain?
They forge your address in "From" without accessing your systems.
What is a DMARC reject policy?
An instruction telling servers to delete messages failing authentication.
Will DMARC stop spoofing entirely?
For compliant providers (Gmail, Outlook), yes. Some servers ignore DMARC.
Do I need SPF to use DMARC?
You need SPF or DKIM. Both recommended.
Why am I getting bounce backs for emails I didn't send?
Spammers spoofing your domain. Bounces return to the forged address.
Can my domain get blacklisted for spoofing?
Yes. Reputation damage affects legitimate email deliverability.
How do I check my DMARC record?
Use DMARC lookup tools or query _dmarc.yourdomain.com.
Does NameSilo provide DMARC?
Configure DMARC yourself via TXT records in the DNS Manager.
NameSilo Staff
The NameSilo staff of writers worked together on this post. It was a combination of efforts from our passionate writers that produce content to educate and provide insights for all our readers.
