DomainKey

DomainKey's is an add on for Postfix

Downloading and Compile DK-Milter
wget http://voxel.dl.sourceforge.net/sourceforge/dk-milter/dk-milter-1.0.1.tar.gz tar -xzf dk-milter-1.0.1.tar.gz cd dk-milter-1.0.1 cp site.config.m4.dist devtools/Site/