# mkdir /etc/postfix/ssl
# cd /etc/postfix/ssl
# openssl req -new -nodes -keyout smtp.theos.in.key -out smtp.theos.in.csr
# cd /etc/postfix/ssl
# openssl req -new -nodes -keyout smtp.theos.in.key -out smtp.theos.in.csr
postfix smtp configuration file
smtpd_use_tls = yes
smtpd_tls_auth_only = yes
smtpd_tls_key_file = /etc/postfix/ssl/smtp.theos.in.key
smtpd_tls_cert_file = /etc/postfix/ssl/smtp.theos.in.crt
smtpd_tls_CAfile = /etc/postfix/ssl/caroot.crt
smtpd_tls_loglevel = 1