Installing and Configuring openDKIM on Debian
This guide will show you how to install and configure openDKIM on a Debian Squeeze VPS. DKIM is a signature/cryptography email authentication technology used to validate that a message was sent by an authorized source. DKIM allows an organization to take responsibility for transmitting a message, in a way that can be verified by a recipient. More information can be found at the official DKIM web site.