Re: [exim] Help with received_header_text

On 2009-09-27 at 19:48 +0200, Vladimir Dyachenko wrote:
> Hello,
>
> I am trying to find out a solution to rewrite a little piece of a header for
> privacy and security reason. I do not want to remove the complete header as
> it is used for loop detection.
>
> To be clear and precise, I would like to change:
> from:
>
> Received: from 200-100-10-10.reverse.fqdn.tld ([200.100.10.10]
> helo=ClientPC)
> to:
> Received: from {SERVER_RDNS} ([{SERVER_IP}] helo={SERVER_NAME})

Those appear to match, unless you mean the literal string "{SERVER_IP}",
etc. Rewriting these in the syntax you describe will result in
ill-formed hostnames, which various anti-spam toolkits will interpret as
a sign of being spam.

So I advise against implementing this.

> I believe this has to do with received_header_text. All example always
> include authentification which I do not want to include in my case.
>
> Can anybody lighten me? Also, where should I place the condition?

To shoot yourself in the foot, you would add something to your Exim
runtime configuration before the first "begin" line; the "begin" takes
you out of the main configuration and into the sub-sections.

You would define received_header_text as a string.

You *very* definitely want to keep $message_exim_id in the header; it
leaks no data about the original mail (it does contain things like an
encoded timestamp of when the mail was received, as part of the way that
a unique string is formed). So you'd set:

received_header_text = "Received: blah blah blah".

Refer to the Exim Configuration docs for the default value, work
stripping stuff from there instead of building up a new header from
scratch.

Dig out RFC 5321 and search for "Received:" and look at the syntax
definition there. Adhere to that, or have your mail classified as spam
by some of the recipients.

Regards,
-Phil