Email DomainKeys Identified Mail (DKIM) Security Failing Validation
Severity Level: Priority 2
Category: Security / Communication
Description:
DKIM is not implemented, leaving emails vulnerable to tampering and spoofing without cryptographic verification.
Impact:
- Increased risk of phishing, BEC, and ransomware.
- Poor email deliverability (e.g., junk folder placement).
- Damage to sender reputation and customer trust.
FFIEC Reference:
- FFIEC IT Examination Handbook (November 2016):
- "DKIM enhances email security and authenticity." (p. 33)
- "Email authentication mitigates spoofing risks." (p. 35)
Recommendations:
- Implement DKIM: Set up selectors in MS365 and publish keys in DNS.
- Combine with SPF/DMARC: Ensure full email authentication suite.
- Test Configuration: Verify DKIM signatures with email tools.