Email spoofing is a common cybersecurity threat that can put businesses, employees and customers at risk. Cybercriminals do this by making fraudulent emails appear to come from trusted senders, tricking people into sharing sensitive information, transferring money or clicking malicious links. Understanding how to prevent email spoofing is an important part of keeping your business secure.
Fortunately, there are several steps businesses can take to reduce the risk of email spoofing and protect their communications.
1. Set Up SPF
One of the first steps to prevent email spoofing is implementing Sender Policy Framework (SPF).
SPF is an email authentication method that allows businesses to specify which mail servers are authorised to send emails on behalf of their domain.
By correctly configuring SPF records, businesses can make it easier for email systems to recognise legitimate messages and identify attempts to impersonate your domain.
However, SPF alone isn’t enough to prevent email spoofing attacks, which is why it should be used alongside other security measures.
2. Implement DKIM
DomainKeys Identified Mail (DKIM) is an email authentication method that helps verify the legitimacy of outgoing emails.
DKIM works by adding a unique digital signature to emails sent from your domain. When the message reaches the recipient, their email provider can check this signature to help verify its authenticity and confirm that the signed content hasn’t been altered during delivery.
Think of DKIM as a tamper-proof seal on a letter.
3. Configure DMARC
DMARC (Domain-based Message Authentication, Reporting and Conformance) works alongside SPF and DKIM. It allows businesses to tell receiving email providers how to handle messages that fail the relevant authentication checks.
Depending on the DMARC policy configured, these messages can be:
- Monitored: Emails are assessed, with reports provided to the domain owner.
- Quarantined: Suspicious messages can be directed to the recipient’s spam or junk folder.
- Rejected: Messages that fail DMARC authentication can be blocked from delivery.
DMARC also generates reports that help organisations identify potential attempts to impersonate their domain.
DMARC enforcement should be introduced carefully. Emails should first be monitored, then put in place a reject policy once legitimate email sources have been verified. Incorrect configurations can otherwise prevent genuine emails from reaching customers.
When configured correctly, SPF, DKIM and DMARC work together to significantly reduce the risk of unauthorised emails being sent using your domain.
4. Review Your Business Email Settings Regularly
Even when email authentication has been configured correctly initially, it’s important to review your settings regularly.
If you introduce a new service that sends emails on your behalf, such as a CRM system, invoicing software or email marketing platform, you should definitely review your settings. If these services aren’t properly included in your authentication configuration, legitimate emails could be incorrectly identified as suspicious.
5. Use Advanced Email Security and Spam Filtering
Advanced email filtering tools examine incoming messages for indicators of phishing, spoofing, malicious attachments and suspicious links.
Depending on the system, these tools can quarantine potentially dangerous emails, display warning messages or prevent harmful content from reaching users.
For businesses using Microsoft 365, it’s worth reviewing the security features available within your existing email environment.
6. Train Employees to Recognise Suspicious Emails
Cybercriminals often rely on people trusting familiar names, company branding or legitimate-looking email addresses.
Providing regular cybersecurity awareness training can help employees recognise warning signs such as:
- Unexpected requests for payments or confidential information.
- Emails creating a false sense of urgency.
- Unfamiliar or slightly altered email addresses.
- Suspicious attachments or website links.
- Requests to bypass normal business procedures.
Employees should question unusual requests, even when an email appears to come from a senior colleague, supplier or trusted customer.
7. Verify Unusual Requests Through Another Communication Channel
If you receive an email from a supplier requesting a change to their bank details, don’t rely solely on the information contained in the message. Instead, contact the supplier using a telephone number you already know is genuine.
The same applies to emails apparently sent by colleagues requesting urgent payments, confidential documents or changes to established processes.
Can Email Spoofing Be Completely Prevented?
While effective email authentication can significantly reduce the risk of criminals sending messages that appear to come directly from your domain, no single measure can eliminate every form of email impersonation.
For example, cybercriminals may register a similar-looking domain name or use a misleading display name to impersonate your business. These techniques can still be used even when your own SPF, DKIM and DMARC records are correctly configured.
That’s why a combination of technical security measures, employee awareness and clear internal procedures is essential.
If you’re unsure whether your business has the right email authentication measures in place, working with an experienced IT support provider like Inventas can help you identify vulnerabilities and strengthen your defences. Get in touch today to learn more.
