Create the PKI directory for mail certificates, if it does not already exist:
$ sudo mkdir /etc/pki/tls/mail
$ sudo chown root:root /etc/pki/tls/mail
$ sudo chmod 755 /etc/pki/tls/mail
Using removable media or some other secure transmission format, install the files generated in the previous
step onto the mail server:
/etc/pki/tls/mail/serverkey.pem: the private key mailserverkey.pem
/etc/pki/tls/mail/servercert.pem: the certificate file mailservercert.pem
Verify the ownership and permissions of these files:
$ sudo chown root:root /etc/pki/tls/mail/serverkey.pem
$ sudo chown root:root /etc/pki/tls/mail/servercert.pem
$ sudo chmod 600 /etc/pki/tls/mail/serverkey.pem
$ sudo chmod 644 /etc/pki/tls/mail/servercert.pem
Verify that the CA's public certificate file has been installed as /etc/pki/tls/CA/cacert.pem, and has the
correct permissions:
$ sudo chown root:root /etc/pki/tls/CA/cacert.pem
$ sudo chmod 644 /etc/pki/tls/CA/cacert.pem