# MINIMAL
# SMTP for incoming mail (port 25)
smtp      inet  n       -       n       -       -       smtpd
  -o smtpd_tls_security_level=may
  -o smtpd_sasl_auth_enable=no
  -o smtpd_recipient_restrictions=permit_mynetworks,permit_sasl_authenticated,reject_unauth_destination

# Submission (port 587) for authenticated users
submission inet n       -       n       -       -       smtpd
  -o syslog_name=postfix/submission
  -o smtpd_tls_security_level=encrypt
  -o smtpd_sasl_auth_enable=yes
  -o smtpd_relay_restrictions=permit_sasl_authenticated,reject