postfix smarthost to relay in same domain

[str tux]

On 9/5/05, Roger Grosswiler <roger at gwch.net> wrote:
> If you have set in postfix $mydomain=mydomain.com, postfix searches that
> user on the local machine, if this mail is also sent by postfix :-D
> 
> set $myhostname correct, and leave #$mydomain, as otherwise postfix thinks
> that is the primary mailserver for this domain.
> 

thanks roger.
and what would be my mydestination?
mydestination = $myhostname, localhost.$mydomain, localhost
or
mydestination = $myhostname, localhost.$mydomain, localhost, $mydomain
?

str