Michael Moritz:
> This is a problem we came upon while setting up the split MX (described
> earlier on this list). On the the smtp gateway I have this in master.cf
>
> smtp inet n - - - 20 smtpd
> -o cleanup_service_name=pre-cleanup
> -o smtpd_proxy_filter=127.0.0.1:10024
> -o smtpd_client_connection_count_limit=10
> -o content_filter=
> # -o content_filter=127.0.0.1:10024
To switch between before/after filters depending on load, use
the Postfix 2.5 stress-dependent feature.
smtp inet n - - - 20 smtpd
-o smtpd_proxy_filter=${stress:127.0.0.1:10024}
-o content_filter=${stress?127.0.0.1:10024}
This, of course, requires that the filter can handle both cases.
In particular, the filter cannot reject mail.
There are patches that back-port stress-dependent behavior to
earlier Postfix releases. See http://www.postfix.org/downloads.html.
Wietse
