Diffie-Hellmann Parameter erstellen

openssl dhparam -out /etc/postfix/dh_512.pem -2 512
openssl dhparam -out /etc/postfix/dh_2048.pem -2 2048

chmod 400 /etc/postfix/dh_512.pem
chmod 400 /etc/postfix/dh_2048.pem