Why Does Email Need to Be Authenticated?
Emails contain various headers that provide useful information about the email, and among these are headers stating who the sender of the email is. While these fields are auto-populated by email programs, it’s possible to modify their content, and email spoofers take advantage of this fact to pretend to be someone else.
Email authentication is critical as it protects an organization’s brand, customers, employees, and partners from spoofing attacks. With email authentication, an organization can prove that every email using its domain actually came from a legitimate sender.
How Does Email Authentication Work?
Companies can prove the authenticity of emails from their domains using the Domain-Based Message Authentication, Reporting, and Conformance (DMARC) protocol. DMARC protects against email spoofing by providing the recipient with the tools to identify spoofed emails and guidance on what to do with these spoofed emails.
The biggest challenge in managing the risk of email spoofing is differentiating between legitimate and spoofed emails. DMARC provides two means of identifying these faked emails:
- Sender Policy Framework (SPF): SPF is a protocol used to specify the IP addresses that are permitted to send emails on behalf of a particular domain. The owner of the domain can specify trusted IP addresses as part of their DNS record. When someone receives an email from this domain, they can verify that the source address is one on this trusted sender list.
- DomainKeys Identified Mail (DKIM): DKIM adds integrity protection and another layer of authentication for email traffic. DKIM enables emails to be digitally signed, with the corresponding public keys included in a domain’s DNS record as well. These digital signatures prove that an email originated from someone with the correct private key and that the content of the email has not been tampered with in transit.
The combination of SPF and DKIM offers strong email authentication and protection against email spoofing. It is also a free solution that can be implemented by adding information to the DNS records associated with a particular domain.
If SPF and/or DKIM identify a spoofed email, DMARC provides instructions to the recipient on how to deal with it. For example, spoofed emails may be automatically dropped, or the recipient may quarantine the suspicious email for further analysis.
How to Authenticate Email
With email authentication protocols such as DMARC, SPF, and DKIM, most of the work lies with the domain owner. They’re responsible for configuring DMARC in their email programs and adding the necessary information to DNS records. Once this is complete, most email programs will automatically perform DMARC verification if it is enabled for a domain. This authenticates the email’s source and — if DKIM is enabled — verifies that it hasn’t been modified en route.
Protecting against Email ATO
Anti-spoofing solutions like DMARC are designed to protect against cybercriminals masquerading as an organization and misusing its domain. In these scenarios, the attacker lacks access to a valid email account for that domain but pretends that their email originated from it. Another major threat to email authenticity and security is account takeover (ATO) attacks. If a legitimate email account within a domain is compromised via breached passwords or other means, then an attacker can legitimately send email from that domain and overcome DMARC checks.
Strong email account security is an organization’s best defense against this threat. Enforcing the use of multi-factor authentication (MFA) for all corporate accounts dramatically reduces the risk that an attacker will be able to compromise an email account and abuse it in their attacks.
Email Authentication and Security with Harmony Email and Collaboration
Spoofing emails are a major threat to a company’s brand reputation and to the users that they attempt to trick. However, they’re only one of several email-based security threats that companies face. Phishing campaigns don’t need to use spoofed addresses and can be used to steal sensitive data, install malware, or trick employees into sending money to an attacker.
While DMARC, SPF, and DKIM protect against email spoofing, they don’t address these other threats. For that, organizations need email security solutions capable of identifying and blocking even the most sophisticated email-based threats.
Check Point Harmony Email and Collaboration provides industry-leading protection against a wide range of email-borne threats. To learn more about how Harmony Email and Collaboration compares to other solutions, check out Check Point’s 2023 Forrester Wave for Enterprise Email Security.
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