[exim] Exim4, Authentication and Sender, Reurn-Path rewritin…

Hi,

I know this has been asked many times but none of my googling requests
gave a suitable answer.
I wan't to get rid of Return-Path and Sender rewriting when an email is
send via an authenticated connexion.

Sending email via my smtp on port 25 without authentication will leave
return-path and sender as configured in my mail client
firstname.lastname@???.
Sending email via the same smtp server on port 465 with an
authentication will change return-path and sender with
login@???

I tried many of the possible solutions I found on the Internet but none
of them worked (submission/retain_sender, submission/domain=,
submission/domain=domain.com/name=...)

Does anoybody have any clue ?

Regards,

Laurent