[exim] Headers privacy

Hello,

For security reasons, could anyone point me in the right
direction in order to get rid of the following header line in
messages locally generated:

Received: from root by host@??? with local (Exim 4.62)

More to that, I would ultimately wish to hide any information from the
inside SMTP hops within my network, so the recipient sees only
a Received from line from my internet mail gateway (without disclosing
exim as the MTA and its's version)

Thank you,

JD