here's the notes I left myself while doing this under 8.10,
maybe they'll help, as well as the web site I got them from which
might be more useful than my notes, I just checked and the site is
still there


From
postfix.state-of-mind.de/.../...auth_mailservers.h\
tml

-Create a file called /etc/postfix/sasl_passwd
-Could this be in /etc/postfix/sasl_passwd/sasl ? This dir already exists...
-Contents:
mail.my-isp.org test:testpass
-File owned by root with 600 mode
-Use "postmap" to create a db file from this
-postmap hash:/etc/postfix/sasl_passwd
-In example, file is in /etc/postfix:
/etc/postfix/sasl_passwd.db
-you only need to run postmap when credentials change
-Enable SMTP AUTH
-In main.cf add:
smtp_sasl_auth_enable = yes
smtp_sasl_password_maps = hash:/etc/postfix/sasl_passwd
smtp_sasl_security_options =
-The last one is NULL for a reason, from the web page, "Finally we
set security options. In our scenario we will allow Postfix to use
anonymous and plaintext authentication. That's why we set the
paramter, but leave it empty"
-Added myself: don't forget to set the relay and port for the relay
-Do a postfix reload "postfix reload"