dkimproxy is an SMTP proxy that signs and/or
verifies Domain Keys Identified Mail (DKIM). It is
designed to work with Postfix. It comprises two
separate proxies: an "outbound" proxy for signing
outgoing email, and an "inbound" proxy for
verifying signatures of incoming email. With
Postfix, the proxies can operate as either
Before-Queue or After-Queue content filters.
