Email Authentication - Is It Enough?

  • Published: Wednesday, Aug. 5, 2020

Email authentication is a method of validating that the sender of an email is authenticated to the domain it purports to be sent from. In other words, if I send you an email from [email protected] it would be run through a series of authentication protocols to verify that the origination of the email matches the domain shown as the sender.

Since SMTP does not perform this service it becomes necessary to implement other measures to accomplish this.  Email authentication has become necessary in order to filter out phishers and spammers. Such messages will either be filtered out as spam or undeliverable. SPF, DKIM and DMARC are good defenses for validating email.

  • SPF – Sender Policy Framework. SPF performs a check to ensure that the sender’s address matches the domain it is sent from
  • DKIM- DomainKeys Identification. With DKIM the sender has a private key used to encode the header in the message. Any servers involved in passing the message along have access to the public key in order to verify that the message is intact and secure.
  • DMARC-Domain Message Authentication Reporting and Conformance. DMARC is the final step in the delivery process. It verifies that the message has passed SPF and DKIM requirements before delivery.

The question “Is email authentication enough?”

There is no ‘silver bullet’ when it comes to email security. Remember, the spammers and scammers are working just as hard to get around your defenses as you are working to put them into place. Hackers may spoof email senders and domains that frequently bypass authentication methods. When the crooks send email through a domain with SPF, DKIM and DMARC configured it can pass authentication and get sent to the innocent recipient.

Education for end users plays a vital role in helping to keep on top of these malicious messages. Learn how to identify and report suspicious email. Technology hardware and configurations cannot be the sole protection.

Resources:

Email Authentication: The Ultimate Guide