No. To almost everything you asked.
Postfix sets a default "mynetworks" parameter which is:
127.0.0.0/8 and your.ip.address.network/netmask where netmask is based on classful subnet rules. If you're on a private address, and you're on the 192.168 .1 net, it'll be /24 - if you're on 10. net, it'll be /8.
It's pretty rare to need to change this on a home based network or a small office network.
run postconf mynetworks to get your setting.
So - how does this work with smtp auth?
If you connect from within "mynetworks", postfix will relay your mail to anyone.
If you've got auth enabled (do you?) then postfix will attempt to authenticate your user, and if that succeeds, will also relay mail anywhere. |