How can I stop someone from using my email address to send spam?
Matthew Whittaker
Co-founder & CTO, Suped
Published 27 May 2025
Updated 16 Aug 2025
8 min read
Discovering that someone is using your email address to send spam can be alarming. You might receive bounce-back messages for emails you never sent, or worse, get complaints from unsuspecting recipients who believe the spam originated from you. This practice, known as email spoofing, can severely damage your sender reputation and create a negative perception of your brand. Understanding how to identify and mitigate these attacks is crucial for maintaining your email deliverability and protecting your professional image.
The good news is that while you cannot entirely prevent someone from attempting to spoof your email address, you can implement robust defenses that make it nearly impossible for their forged emails to reach inboxes. This involves a combination of technical configurations and proactive monitoring. My goal here is to walk you through the steps to protect your domain and ensure your legitimate emails continue to land where they should.
We often see situations where businesses are caught off guard, with their support inboxes flooded with replies to fraudulent messages. This article will explain what you can do, from foundational email authentication to ongoing vigilance and incident response.
Understanding email spoofing
Email spoofing is the act of forging an email header to make it appear as though the email originated from a different source. Spammers do this to trick recipients into opening malicious emails or to bypass spam filters by leveraging a seemingly legitimate sender's reputation. It's important to differentiate spoofing from a compromised email account, where an unauthorized party gains actual access to your mailbox. With spoofing, the attacker doesn't necessarily have access to your account; they are simply faking the From address.
The core vulnerability lies in the original design of email protocols, which didn't include robust mechanisms for sender verification. This is why email authentication protocols like SPF, DKIM, and DMARC were developed later to address these security gaps. Without these, anyone can theoretically put any address in the From field, much like writing a fake return address on a physical letter.
Spammers exploit this by using your domain to send deceptive emails, which can lead to your domain being added to a blocklist (or blacklist). This affects your legitimate email campaigns, causing your important messages to be flagged as spam or rejected entirely. The primary way to combat this is by implementing and enforcing email authentication protocols.
Implementing email authentication protocols
The most effective way to prevent email spoofing is through the proper configuration of email authentication protocols: Sender Policy Framework (SPF), DomainKeys Identified Mail (DKIM), and Domain-based Message Authentication, Reporting, and Conformance (DMARC).
SPF allows you to specify which IP addresses are authorized to send emails on behalf of your domain. DKIM provides a cryptographic signature that verifies the email has not been tampered with in transit. DMARC builds upon SPF and DKIM, giving you the power to tell receiving mail servers what to do with emails that fail authentication, such as quarantining or rejecting them. For a deeper dive, read our simple guide to DMARC, SPF, and DKIM.
Implementing DMARC policies
To stop spoofing, you need to implement DMARC with a policy of p=quarantine or p=reject. A p=none policy only provides monitoring and reporting, but it doesn't prevent spoofed emails from reaching inboxes. Moving to enforcement policies like quarantine or reject ensures that receiving mail servers will either place unauthenticated emails in the spam folder or block them entirely. If you're currently using p=none, consider our guide on how to safely transition your DMARC policy.
Properly configuring these records can be complex, especially for domains with multiple sending services. It's crucial to ensure all legitimate email senders are authorized in your SPF record and that DKIM is correctly signed for all outbound mail. Otherwise, you risk blocking your own legitimate emails.
Monitoring and response strategies
Once DMARC is set up, monitoring your DMARC reports is essential. These XML reports provide valuable insights into who is sending email purporting to be from your domain, whether it's legitimate traffic or spoofing attempts. By analyzing these reports, you can identify unauthorized senders and adjust your DMARC policy as needed.
If you receive complaints about spoofed emails, try to obtain the full email headers from the recipients. A simple forward often strips crucial header information. Full headers can reveal the true origin of the email, helping you confirm if it originated from your infrastructure or an external spoofer. You can also inspect the email's HTML for any tracking URLs that might provide clues about the sender. Learn more about how to interpret these with our guide on troubleshooting DMARC reports.
Should your domain end up on a public blocklist (or blacklist) due to spoofing, you'll need to work on delisting it. This typically involves proving that you have implemented the necessary security measures to prevent future abuse. Continuous monitoring of major blocklists is a recommended practice to quickly detect and address any listing issues that may arise.
Identifying the threat
Email headers: Look for discrepancies in Received or Authentication-Results fields.
Content analysis: Check for suspicious links, generic greetings, or urgent calls to action common in phishing.
DMARC reports: Regularly review aggregated and forensic reports for failed authentication attempts.
Proactive measures and ongoing vigilance
Beyond technical configurations, several proactive measures can help prevent your email address from being abused. This includes general cybersecurity hygiene and careful management of your email presence online. The more difficult you make it for spammers to acquire or misuse your email, the safer you'll be.
Always use strong, unique passwords for your email accounts and enable two-factor authentication (2FA) wherever possible. This is your first line of defense against actual account compromises, which can be even more damaging than spoofing. Be cautious about where you post your email address online; spammers often scrape websites for email addresses.
For signing up for newsletters or less critical services, consider using email aliases or a secondary email address. This reduces the exposure of your primary email. If you find your domain frequently affected by spoofing, despite DMARC, it might indicate a broader issue with how your email addresses are being harvested or shared.
Reactive measures
DMARC enforcement: Move to a p=quarantine or p=reject policy.
Header analysis: Request full headers from recipients to identify the true sending source.
Customer service response: Develop a clear, concise boilerplate explanation for complaints.
Blocklist delisting: Address any blocklist entries by implementing fixes and requesting removal.
Proactive measures
Strong passwords & 2FA: Secure your actual email accounts against compromise.
Email exposure: Avoid posting your primary email address on public websites.
Aliases/secondary emails: Use these for non-critical sign-ups to reduce spam to your main inbox.
Staff training: Educate employees on identifying and reporting phishing attempts.
Protecting your email ecosystem
Effectively stopping someone from using your email address to send spam (or email spoofing) is primarily about strengthening your domain's email authentication. Implementing and enforcing DMARC with a policy of quarantine or reject is the most powerful tool you have. This tells receiving mail servers to treat unauthenticated emails from your domain with suspicion, effectively preventing most spoofed messages from reaching their intended targets.
However, the process doesn't end there. Continuous monitoring of DMARC reports, vigilance against phishing attempts, and proactive cybersecurity habits are crucial for long-term protection. By combining technical solutions with smart operational practices, you can significantly reduce the impact of email spoofing and safeguard your domain's reputation and deliverability. Keep an eye on your domain's health and be prepared to respond quickly if new threats emerge.
Views from the trenches
Best practices
Implement DMARC with an enforcement policy (quarantine or reject) as soon as possible after monitoring.
Regularly monitor your DMARC reports to identify all legitimate sending sources and unauthorized spoofing attempts.
Educate your customer support team on how to respond to complaints about spoofed emails.
Secure all email accounts with strong, unique passwords and multi-factor authentication.
Maintain a clear understanding of your authorized email senders and ensure they are properly configured with SPF and DKIM.
Common pitfalls
Leaving DMARC policy at 'none' for too long, which only monitors and doesn't prevent spoofing.
Not collecting full email headers from affected recipients, making it harder to trace the spam source.
Ignoring DMARC aggregate reports, missing crucial data on unauthorized domain usage.
Failing to update SPF records when adding new email sending services, potentially causing legitimate emails to fail authentication.
Not having a clear communication plan for customers who report receiving spoofed emails.
Expert tips
Focus on incremental DMARC deployment, starting with monitoring and gradually enforcing stricter policies.
Automate DMARC report analysis with a DMARC monitoring tool to simplify the process.
When responding to complaints, provide clear instructions for how recipients can check email headers themselves.
Consider using a service that allows you to generate temporary or alias email addresses for public sign-ups.
Periodically review your domain's reputation with tools like Google Postmaster Tools for early warning signs.
Expert view
Expert from Email Geeks says implementing DMARC on your domain, ensuring your SPF contains -all, and moving to a quarantine or reject policy, is essential to limit email spoofing effectively.
2022-01-01 - Email Geeks
Expert view
Expert from Email Geeks says DMARC at quarantine or reject policy is necessary, because a 'none' policy will not stop email spoofing.
2022-01-05 - Email Geeks
Final thoughts on securing your email
Stopping someone from using your email address to send spam is primarily about bolstering your domain's email authentication. The most significant step you can take is to implement and enforce DMARC with a policy that instructs receiving mail servers to quarantine or reject emails that fail authentication. This directly tells mailbox providers like Google and Yahoo to block emails that are spoofing your domain.
While you can't prevent every attempt at spoofing, these strong authentication measures, combined with proactive monitoring of DMARC reports and good cybersecurity hygiene, will significantly reduce the success of such attacks. This approach ensures your legitimate communications remain secure and your sender reputation intact.
Google and 
Yahoo to block emails that are spoofing your domain.
