/etc/postfix/main.cf
smtpd_relay_restrictions = permit_sasl_authenticated defer_unauth_destination
smtpd_sasl_auth_enable = yes
smtpd_sasl_security_options = noanonymous
smtpd_client_restrictions = permit_sasl_authenticated
/etc/postfix/sasl/smtpd.conf
pwcheck_method: auxprop
auxprop_plugin: sasldb
mech_list: PLAIN LOGIN CRAM-MD5 DIGEST-MD5
saslpasswd2 -c username -u domain.name
cp /etc/sasldb2 /var/spool/postfix/etc/
chown postfix:postfix /var/spool/postfix/etc/sasldb2
