dk-filter 1.0.0.dfsg-1.2 (arm64 binary) in ubuntu trusty

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