Hello,
may I have just a confirm I had done well and one question?
I want to send mail from my linode machine but Ii do not want to receive anything.
I have setup postfix and set
inet_interfaces = loopback-only

Reading the postfix docs I am not sure if I have with this command also disabled sending the SMTP from outside?
Also I send on port 25 to my future,possible,any user. Is this safe since I will send login data to my service (passwords and such)?
What I do not know is how things works between mail servers. If I send on port 25 is the message unencrypted through all the way to the user or messaging between my postfix smtp server and the rest of the world is encrypted?

thanks
Nenad

I have added to postifx main.cf
smtpd_client_restrictions = permit_inet_interfaces
but maybe it was not necessary beacause even without this I couldn't send with remote telnet the email (relay access denied).

You could just block the SMTP ports 25 and 465 with iptables (firewall). Then you don't have to mess with your mail server installation.

Thanks
I did
iptables -A INPUT -s 0.0.0.0 -p tcp --dport 25 -j DROP
iptables -A INPUT -s 0.0.0.0 -p tcp --dport 465 -j DROP

and it seems it works

Nenad