exim4: Hide local mail name in outgoing mail. domainname for dsl user

[Leonardo Canducci <leonardocanducci@yahoo.it>]

is that a good choice for a standalone pc with dsl fulltime internet 
access configured as "mail sent by smarthost; received via SMTP or
fetchmail"?
shouldn't the same task be handled by /etc/email-addresses file?

one more question: shuld such a pc (connected via a dsl provider) have a
domain name if I don't have any registered domain such as foo.org? 
would it make sense using my provider's domain name (even if my email 
address is not user@provider.org)?
in other words, what's the right answer for "domain-name" question when
configuring netbase package in such a case?

thanks.
Leonardo Canducci