Hi Wietse On Tue, 2012-08-14 at 17:02 -0400, Wietse Venema wrote: > Many sites have external content filters as described above. > > 1 - Postfix receives mail from the network with the Postfix SMTP > server. This may be an original submission or not. Or, Postfix > receives mail with the Postfix sendmail command. This may also > be an original submission or not. > > 2 - Postfix sends the mail through the filter via the Postfix SMTP > client or via the pipe(8) delivery agent. The filter sees the > original recipients; virtual aliasing happens after the filter. > > 3 - Postfix receives a perhaps modified message from the filter via > the Postfix SMTP server or via the Postfix sendmail command. > > 4 - Postfix does some virtual alias expansions on recipients, and > then it delivers the message to local or remote recipients. > > How should SRS work in this configuration?
SRS will work if the proposed scheduler protocol is run on the 4th step you described. At this point, the SRS application will make a request "(sender, recipients)" and receive "(sender, transport, nexthop, translated_recipients, tag)" replies. The recipients would be grouped into clusters, and translated_recipients would be inspected to decide if the recipients are local or not. The tag would be inspected to decide if the sender is local or not. If both are remote, then the envelope-from will be SRS-munged. In this description, I'm assuming that Postfix was configured in such a way that meaningful tags can be chosen on the appropriate smtpd instances. This means that two "mail paths" would have to be configured, for inbound and outbound mail. Thus, one would have to setup two different smtpd instances, each connected to their own content_filter instance, which would in turn send the messages back to Postfix via two more separate smtpd instances. It is in these two last instantes that the tag could be applied. Andre
