What is DKIM?
DomainKeys Identified Mail (DKIM) is a popular email authentication technology that allows for a domain to prove it is responsible for a message and that that message was not altered as it traveled the delivery path.
DKIM is a standard based on two previous authentication technologies, the DomainKeys standard from Yahoo and the Identified Internet Mail standard from Cisco. DKIM was formalized as a draft standard by the IETF in RFC 4781, published in May of 2007 [ https://www.rfc-editor.org/rfc/rfc6376.txt ].
The basis of DKIM is that with the use of public keys published into DNS, messages can be authenticated in a non-path-related method. The authentication process revolves around the creation and decoding of what is called the DKIM signature. DKIM signatures are inserted into the header of an email message. A hash of the body and select header items is created and used in a calculation along with a private key value to create a message signature that can be decoded properly only with the public key which is posted in a domain's DNS.
How does SocketLabs On-Demand platform authenticate mail with DKIM?
Each and every message that processes through the SocketLabs On-Demand Platform is automatically signed with a DKIM signature that authenticates email-od.com as the point of origin for your messages. This allows every message processing on our platform to properly authenticate at the major service providers. No action is required for DKIM authentication to occur.
SocketLabs also allows the ability to add customized DKIM signatures to your messages. Customized DKIM signatures are in addition to the email-od.com signature that is already added to each and every message. For more information about customizing your DKIM signature please see our knowledge base articles specifically on our two signing options.
SocketLabs On-Demand DKIM Signing - Custom Option: http://support.socketlabs.com/kb/113/
SocketLabs On-Demand DKIM Signing - Advanced Option: http://support.socketlabs.com/kb/114/
Combined with our use of a Variable Encoded Return Path [ VERP - http://support.socketlabs.com/kb/99/ ] SocketLabs, automatically, fully authenticates messages sent through through its network. Authentication checks by receiving mail servers will see correlation between between, DKIM, SPF, rDNS, and the Return Path domain.
Further questions about DKIM and authentication should be directed to the SocketLabs Support department: email@example.com