Rob Maidment:
> Some confusion here, probably because I have used the wrong
> terminology. When I said I have a content filter that needs to
> influence how a message is routed, I meant a content filter that is
> implemented as an SMTP proxy sitting between two Postfix instances.
>
> That said, Wietse's response led me to a solution I think:
>
> The SMTP proxy can add an X-header indicating where the message should
> be routed.
> In the upstream Postfix instance I can configure header_checks to
> check for the X-header and return a FILTER response based on the
> header value using a regex.
> I'll need to take steps to ensure this can't be exploited, e.g. by
> stripping the X-header if it exists in the downstream Postfix
> instance, or in the SMTP proxy.
What problem are you trying to solve? Please describe the problem,
not the solution (adding a header that triggers a FILTER action).
Wietse
