Separation of log facilities

Hi,
I'd like to send logging for emails sent from a specific IP to a different syslog facility. I am able to define
the port used by the sending machine and have configured a new instance of smtpd to listen on 26 with the '-o
syslog_facility=' parameter. This successfully captures the connections coming in on 26 but I'd also
like to send the smtp side of things to the same facility. I was thinking transport maps but seems to only be
able to examine rcpt addresses.

Is there a more simple way to do this. Ultimately I'd like to have an instance of postfix (both smtpd and smtp)
listening on a separate port and logging to a difference facility so I can isolate log information without
disrupting current activity.

Thanks,

Rob Kelledy