Dkfilter is a DomainKeys implementation for the
Postfix mail transfer agent. It is implemented as
two filters (or SMTP proxies). There is an
"outbound" filter for adding DomainKeys signatures
to outgoing email and an "inbound" filter for
verifying signatures of incoming email. The
filters can be plugged into Postfix as either
Before-Queue or After-Queue Postfix content
filters. For more information about DomainKeys,
see http://antispam.yahoo.com/domainkeys.
