DKIM stands for Domain Keys Identified Mail and is a protocol for email authentication that allows recipients to verify whether an email was actually sent and authorized by the domain owner
In other words, DKIM will enable organizations to take ownership of the emails sent through their domains by giving them a digital signature that mailbox providers can easily demarcate. DKIM is used to detect phishing emails from genuine ones using DKIM signature as the primary means of verification. The DKIM signature is typically added as a message header and secured with cryptographic encryption.
The DKIM signature is usually invisible to end-users or email recipients and mainly functions on a server level. The receiving server identifies whether an email is signed with the DKIM signature of the organization whose domain name is used. Once the verification is done, the email with all its constituent messages and attachments is forwarded to the end user’s mailbox.
Domain Keys Identified Mail began in 2004 as a merger of two existing technologies – enhanced DomainKeys from Yahoo and Identified Internet Mail from Cisco. This new technology eventually became a widely adopted email authentication technique. DKIM is a testament to the integrity of a message’s content and verifies that its contents have not been changed in transmission. In addition, it decreases the chances of emails not being delivered – a problem that has cost companies many loyal customers.