smilla is a SMIMEA aware milter.
It implements draft-ietf-dane-smime as specified by the IETF DANE WG.
smilla is written in Python. It queries the SMIMEA-Record (Record-Type 53) in the DNS zone of the email recipient for an x509 certificate. If such a record is found, it will encrypt the mail using the fetched certificate.
The SMIMEA record for the x509 certificate must be created with SMIMEA options "3 0 0"