Postfix sender specific smtp with auth

main.cf

sender_dependent_default_transport_maps = hash:/etc/postfix/sender_transport

smtp_sasl_auth_enable = yes
smtp_sasl_password_maps = hash:/etc/postfix/sasl_passwd
smtp_use_tls = yes
smtp_sasl_security_options = noanonymous

master.cf

outsmtps   unix  y       -       y       -       -       smtp
    -o smtp_tls_wrappermode=yes
    -o smtp_tls_security_level=encrypt
outsmtp    unix  y       -       y       -       -       smtp
    -o smtp_tls_wrappermode=no
    -o smtp_tls_security_level=encrypt

sasl_passwd

[sakataki.ext.b2.fi]:465        aketzu:foobar
[smtp.iki.fi]:465               aketzu:foobar

sender_transport

#TLS wrapping
@iki.fi         outsmtps:[smtp.iki.fi]:465

#STARTTLS
@tracon.fi      outsmtp:[sakataki.ext.b2.fi]:465