What the heck is DKIM and DMARC?

Despite several years of talk of its demise, email is still a vital part of business communication.  This critical component of your business is being hampered by continuous spam emails and  phishing attempts, disrupting the productivity of your workforce.

Several solutions have been put in place to try and mitigate the threat, including pre-server filtering and phishing training products such as Proofpoint, Cofense and Knowbe4.  But these solutions still do not stop spam, phishing and impersonation spoof attacks.

This is where DMARC and DKIM come in.  Sender Policy Framework (SPF), Domain Keys Identified Mail (DKIM) and DMARC or Domain-based Message Authentication, Reporting and Conformance work together to protect email senders and recipients from spam, spoofing and phishing.

DMARC is an email validation tool jointly created by PayPal, Google, Microsoft and Yahoo.

• DMARC allows you to tell receiving servers what to do with outgoing messages that don’t pass SPF or DKIM
• DMARC also lets you request reports from email servers that get email from your organization to identify possible authentication issues and malicious activity SENT from your domain.

In summary, DMARC tells receiving mail servers what to do when they get a message that appears to be from your organization, but doesn’t pass authentication checks, or doesn’t meet the authentication requirements in your DMARC policy record. Messages that aren’t authenticated might be impersonating your organization, or might be sent from unauthorized servers.

DKIM allows the RECEIVER to check that an email that claimed by be from a specific domain, was indeed authorized by the owner of the domain.  It achieves this by attaching a digital signature, linked to a domain name, to each outgoing email.  DKIM in itself does not “filter” or identify spam, but widespread use can prevent spammers from forging the source address of their messages and also identify email that is known NOT to be spam, so it gets delivered.  DKIM allows spam filters to quickly identify the bad email!

Now this will not stop your organization from sending out spam, should it be infiltrated and the bad guys get access to an authenticated mailbox.  It is still critical to have your IT support company or department manage your network security and implement Multi-factor authentication solutions.