On 5/2/2013 4:14 PM, Michael Ionescu wrote: > > > On 02.05.2013 17:57, Noel Jones wrote: >>> [...] >>> prequeue proxy virusfilter [...] precludes >>> rewriting the Received: header [...] >>> QUESTION 1: Is this correct? >>> [...] >>> QUESTION 2: Is there a definitive overview of all the ways postfix >>> detects loops and at what stages these are employed? (I mean aside from >>> the source code.) :-) >>> [...] >>> QUESTION 3: Can one make sender-based-routing conditional [...]? >>> QUESTION 4: Does this also work with an smtpd configured with a >>> pre-queue proxy filter? >>> [...] >>> Thanks for your insight! >>> Michael >>> >> >> >> "C" Multiple postfix instances is the preferred solution. Postfix >> supports multiple instances on the same machine quite well. The >> added overhead to the machine is negligible. There is some extra >> administration, but the upside is you can easily do things that are >> not possible (or really ugly) in a single instance. >> >> http://www.postfix.org/MULTI_INSTANCE_README.html >> >> >> -- Noel Jones >> > > Thanks Noel. While this may be generally correct, I come from using > qmail and having to compensate its shortcomings by both extensive > patching and ultimately placing multiple installations on each machine. > > I do not want to go back to having multiple MTA installations on a > machine because of the drawbacks in administration, even in view of > postmulti. Therefore I am explicitly asking about the other solutions I > have in mind and am open for ones that I have not thought of. > > Michael >
Write 100 times on the blackboard: "postfix is not qmail" Postfix transport features are global to each instance, and are non-conditional. If you're using sender dependent transports, you're going to have a hard time without multiple instances. If you can use something else to correctly route the original mail, you have a chance of it working without multiple instances. One thought that comes to mind is submitting the original mail on a specific port that has a -o content_filter=smtp:[remote.smtp.server]. Another possibility is a policy service that examines the detects the "special" mail through some combination of source IP and sender, and returns FILTER smtp:destination when appropriate. -- Noel Jones
