Bonjour,

> I desperatlly seek a good view of dealing with an external relay smtp
> on the Isp side requiering simple authentification.
>
>
> BUT I do not understand how to make the Postfix make **simple**
> authentification (no TLS , NO SSL - same id /pw as POP ).

I went through that recently. There is an excellent article which describes
the steps here:

http://postfix.state-of-mind.de/patr...ilclients.html

Make sure that postfix has been compiled with TLS support as described
in the article above.

Basically, I added the following lines in main.cf:

###############################################
# This is to allow authentication when #
# Postfix acts as a mail client to other mail #
# server for relay. #
###############################################
#
smtp_sasl_auth_enable = yes
smtp_sasl_security_options =
smtp_sasl_password_maps = hash:/usr/local/etc/postfix/sasl_passwd

The file sasl_passwd contains the following:

pop3.mail.server your_email@mail.server:your_password

J'espere que cela vous aidera
Bonne chance
Jeff