DomainKeys

is a simple email authentication system that was designed to verify an email sender’s domain and the integrity of the message. This system defines the integrity or the trustworthiness of information over a particular broadcast’s life-cycle.

The DomainKeys program was published in mid-2007. Soon after, the program merged with Identified Internet Mail. Today, it is now DomainKeys Identified Mail, or DKIM. The ultimate goal of this program is to allow the mail recipient to distinguish legitimate messages in their mail stream from spam messages. This program associates email messages with their sender’s domain, allowing a person or organization to take responsibility for the messages that they send. To allow for this responsibility, DKIM sets up a digital signature that is validated by the recipient.

With DKIM, the sender will insert a signature in the header of each email that they send. This header area gives their DKIM signature, showing their source addressand is an essential part of the program. The signature eliminates forged addresses and content by spammers. Forged addresses prevent users from complaining to the actual sender about incoming messages; instead of returning to the spammer, the message will go to a user that did not send the message. These forgeries also make it difficult for recipients to determine between actual email transmissions and spam messages. However, widespread use of DKIM can prevent spammers from forging source addresses in their messages. As spammers are forced to show their actual source domains, filtering techniques will better recognize spam email.