Hi I wish to set up a multi instance filter-before-queue incoming edge relay postfix 3.1.* configuration. I've been studying the MULTI_INSTANCE_README which describes only the filter-after-queue multi setup and the SMTPD_PROXY_README which describes the filter-before-queue non-multi setup. I've not been able to deduce the answer to the following from this and the other postfix documentation.
QUESTION: what is the interaction between smtpd_proxy_filter and the various transport settings? SPECULATION: In the postfix-recv instance (that receives email from the internet and conveys it to the filter) setting smtpd_proxy_filter=127.0.0.1:10025 will make that instance ignore any values set for the various transports, such as relay_transport, fallback_relay, virtual_transport, default_transport, transport_maps, etc. This implies that a transport table can not be used to discard email to select recipients. Further the instance will ignore several of the actions in an access(5) table, such as FILTER, HOLD, and REDIRECT. It is possible that BCC and DISCARD do work. And the other actions should work. However there is no PROXY_FILTER action to allow one to selectively do filter-before-queue while defaulting to filter-after-queue. Thanks Regards, Todd Olson Cornell University
