Author: W B Hacker Date: To: exim users Subject: Re: [exim] Exim4, Authentication and Sender,
Reurn-Path rewriting (exim-4.63-10.el5)
Laurent Rahuel wrote: > 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
You really, really do not want to permit that.
I hope it was only for a SHORT testing period, was limited to local
recipients only, and otherwise protected by source IP restriction,
cert-matching, yadda, yadda.
If nothing else, your MUA should almost certainly have failed the rDNS
test that is a 'Very Good Idea' to apply on port 25 arrivals. That
discriminates 'at once' between real servers with the proper records
required ... and the brazillion legions of 'bots ... who have them not.
Which test you can then EXEMPT a logged-in-with-TLS user from on port 587.
