Coming back for news.
Did a fresh new installation following the same Howto and i still can't send any emails outside my LAN.
Is it normal?
I configured postfix as an "Internet site with smarthost", filled the "relayhost = " in the postfix main.cf and still impossible to get out.
I always have this in /var/log/mail.log:
Sep 28 15:32:46 smtp postfix/smtpd: 750421022BC: reject: RCPT from Noon-PC.home[192.168.1.10]: 550 5.1.1 <firstname.lastname@example.org>: Recipient address rejected: User unknown in virtual mailbox table; from=<email@example.com> to=<firstname.lastname@example.org> proto=ESMTP helo=<[192.168.1.10]>
I tried other installations and that configuration works. Something in this tutorial blocks outside going mails, just can't find what...