On Mon, 18 Feb 2008 14:16:36 -0800 (PST)
adriano.ghezzi@gmail.com wrote:

> solved!
> simply postfix don't permit to be used as smtp server when you are
> outside from your lan
> :-<

Not by default, which is a good thing.

You need to tell Postfix what is acceptable to relay and which methods
to use to tell the difference.

Chris