Defending Against Email Spoofing

The SMTP protocol used for sending emails lacks built-in authentication, making it trivially easy for attackers to forge the 'From' address. To combat this, three core DNS-based security protocols were developed: SPF, DKIM, and DMARC. Our Email Security Checker analyzes your domain's DNS configuration to validate the syntactic correctness and enforcement strength of these crucial records.

The Phishing Epidemic

Business Email Compromise (BEC) and phishing are the leading vectors for ransomware infections and financial wire fraud. If your domain lacks a strict DMARC policy (p=reject), attackers can send perfectly crafted emails pretending to be your CEO or invoicing department. These emails will pass through spam filters because, technically, there is no policy instructing the receiver to block them.

How to Secure Your Email Infrastructure

• Flatten SPF Records: SPF records have a strict 10-DNS-lookup limit. Exceeding this causes SPF to break entirely. Use SPF flattening if you use many third-party email senders.
• Implement DKIM Signing: Ensure all legitimate mail servers (including marketing tools like Mailchimp or CRM tools like Salesforce) cryptographically sign outgoing emails with DKIM.
• Enforce DMARC gradually: Start with a DMARC policy of p=none to monitor reports, fix delivery issues, then escalate to p=quarantine, and finally p=reject.