By Heather Diaz
As a community bank, your reputation is your most valuable asset. In the digital age, this reputation is intrinsically tied to your domain reputation and the security of your communications. Email authentication using SPF, DKIM, and DMARC, is no longer optional—it’s a critical layer of defense against phishing, spoofing, and other email-based fraud that targets the banking sector.
Understanding SPF, DKIM, and DMARC
These three acronyms represent the modern standard for email security, working in concert to verify that an email truly originates from your authorized systems.
- Sender Policy Framework (SPF):This is a DNS record that lists all the IP addresses and mail servers authorized to send emails on behalf of your domain. A receiving server (e.g., Google, Microsoft) checks the sender’s IP against this list. Think of it as a door person checking a guest list at a bank event.
- Domain Keys Identified Mail (DKIM):This protocol adds a digital signature to the email’s header using a form of encryption. This allows the receiving server to verify that the message content hasn’t been tampered with in transit and confirms the sending domain’s identity. It’s like a tamper-proof seal and an official signature.
- Domain-based Message Authentication, Reporting, and Conformance (DMARC):This builds on SPF and DKIM. It’s the policy layer that tells the receiving email server what to do if an email fails both SPF and DKIM checks—options are “none” (monitoring), “quarantine” (spam folder), or “reject” (block delivery). Critically, DMARC also requires alignment and provides valuable reports on all emails using your domain, legitimate or otherwise.
Domain Reputation and Deliverability in Banking
For community banks, an unauthenticated email domain is an open invitation for a fraudster to spoof your address to steal funds or customer credentials. When your domain is frequently associated with fraudulent activity because it’s not protected, your domain reputation plummets.
A poor domain reputation leads to:
- Lower Email Deliverability:Legitimate, critical communications—like account statements, alerts, and password resets—are more likely to be sent straight to a customer’s spam folder or blocked entirely.
- Loss of Customer Trust:Customers who are frequently exposed to seemingly authentic phishing emails using your brand will lose confidence in your security and, ultimately, your bank.
- Proper implementation of SPF, DKIM, and DMARC ensures your genuine mail is authenticated and trusted by major mailbox providers, resulting in higher inbox placement and preserving your vital reputation.
The Importance of Strict Alignment and Enforcement
When configuring DMARC, the settings for alignment and policy are vital for maximum protection:
- Strict Alignment (aspf=s and adkim=s):Alignment is the process of matching the domain in the visible “From” address (what the customer sees) with the domain authenticated by SPF and DKIM. Strict alignment(indicated by the tags aspf=s for SPF and adkim=s for DKIM) requires an exact match of the domains. This provides the highest level of protection by preventing attackers from using a subdomain(like secure.yourfirst.bank) to spoof the main organizational domain (yourfirst.bank).For a bank handling sensitive data, this heightened security is strongly recommended.
- DMARC Enforcement (p=reject or p=quarantine):A DMARC policy set top=reject or p=quarantine(known as enforcement) instructs receiving servers to actively block or flag emails that fail authentication. Setting the policy to p=reject offers the maximum protection, helping to ensure that fraudulent emails using your domain will not reach the customer’s inbox. Never leave your policy at p=none indefinitely, as this only monitors activity without actively stopping spoofing.
Leveraging Authentication with a Verified .Bank Domain
The value of robust email authentication is dramatically amplified when combined with a .Bank domain.
The .Bank domain extension is reserved exclusively for verified banks. It includes advanced security requirements, and crucially, mandates the use of DMARC at an enforcement policy to help secure a bank’s email channel.
By combining DMARC’s power with the verified trust of a .Bank domain, banks get:
- Enhanced Customer recognition: Your customers can confidently identify your legitimate emails and websites by simply looking for .Bank.
- Maximized Fraud Prevention:The mandatory security controls and DMARC enforcement of the .Bank ecosystem ensure your domain is significantly harder for criminals to spoof, reducing the risk of BEC and phishing attacks.
For community banks, this combined strategy creates a more secure, trustworthy digital presence, ensuring your critical communications are delivered and your customer relationships remain protected. For more information, visit https://register.bank.
About the Author
Heather Diaz, Vice President, Compliance and Policy, at fTLD Registry Services, provides strategic leadership for the exclusive top-level domain extensions .Bank and .Insurance.
Heather leads initiatives to enhance security compliance, and ensure they continue to offer innovative website and email security solutions for banks, insurers, producers, and their customers.
Passionate about creating a secure digital ecosystem, Heather actively supports technical initiatives aimed at bolstering trust in these top-level domains and within the DNS. To meet with Heather about .Bank or .Insurance, visit: https://meetings.hubspot.com/heather-diaz.