I'm using Ispconfig 2 on a suse 11 installation.
I have added the suggested lines
mynetworks = 127.0.0.0/8
smtpd_recipient_restrictions = permit_sasl_authenticated,permit_mynetworks,reject _unauth_destination
My mail server is not an open relay, and users have to authenticate except when sending to an internal user. So anyone using my smtp server can send an email to any user @mydomain without any authentication.
Can I limit this or is that a part of normal mail server operation. The problem of course is spam
. I'm using spamassasin, but a lot of spam still get's delivered.