dkim-filter 2.5.1.dfsg-0ubuntu1 (amd64 binary) in ubuntu hardy

 Implements a Sendmail Mail Filter (Milter) for the DomainKeys
 Identified Mail (DKIM) standard. DKIM provides a way for senders to
 confirm their identity when sending email by adding a cryptographic
 signature to the headers of the message.
 .
 The dkim-milter implements both signing and verification.