OK, got it working.
From the basic main.cf I did made some changes and it now works. A diff between the initial installed main.cf and my working one is:
679,687c679< #relayhost =
<
< relayhost = [smtp.gmail.com]:465
< ########### Required for GMail relay ##########
< smtp_tls_wrappermode = yes
< smtp_tls_security_level = encrypt
< ###############################################
<
<
---
> relayhost =
717,719c709,711
< smtp_sasl_auth_enable = yes
< smtp_sasl_security_options = noanonymous
< smtp_sasl_password_maps = lmdb:/etc/postfix/gmail
---
> smtp_sasl_auth_enable = no
> smtp_sasl_security_options =
> smtp_sasl_password_maps =
Note /etc/postfix/gmail is my local version of sasl_passwd.
If you need my working file just ask for it.