You do not need to change anything else in it, as the last setting for any option is the one that is saved.
{{Text|Text=#### Gmail SSL SMTP Relay
relayhost <nowiki>=</nowiki> [smtp.gmail.com]:587
#auth smtp_sasl_auth_enable <nowiki>=</nowiki> yes smtp_sasl_password_maps <nowiki>=</nowiki> hash:/etc/postfix/sasl_passwd
#tls smtp_use_tls <nowiki>=</nowiki> yes smtp_sasl_security_options <nowiki>=</nowiki> noanonymous smtp_sasl_tls_security_options <nowiki>=</nowiki> noanonymous smtp_tls_note_starttls_offer <nowiki>=</nowiki> yes tls_random_source <nowiki>=</nowiki> dev:/dev/urandom smtp_tls_scert_verifydepth <nowiki>=</nowiki> 5 smtp_tls_key_file <nowiki>=</nowiki> /etc/pki/tls/gmail_relay/server.key smtp_tls_cert_file <nowiki>=</nowiki> /etc/pki/tls/gmail_relay/server.pem smtpd_tls_ask_ccert <nowiki>=</nowiki> yes smtpd_tls_req_ccert <nowiki>=</nowiki> no smtp_tls_enforce_peername <nowiki>=</nowiki> no}}
Create /etc/postfix/sasl_passwd file with your Gmail login credentials that looks like below:
{{Text|Text=gmail-smtp.l.google.com user@gmail.com:password