Falko Timme writes “DomainKeys is an anti-spam software application in development at Yahoo that uses a form of public key cryptography to authenticate the sender’s domain. dkfilter is an SMTP-proxy designed for Postfix. It implements DomainKeys message signing and verification. It comprises two separate filters, an outbound filter for signing outgoing email on port 587, and an inbound filter for verifying signatures of incoming email on port 25. This document shows step-by-step how to install dkfilter for Postfix to deploy DomainKeys signing and verification.”
Link: howtoforge.com
