* Wietse Venema: > Perhaps better, Milter D defers the message immrediately, and Postfix > retries a few minutes later, until the necessary data is available.
Indeed. Having milter D block until the required data becomes available would tie up too many resources. Better to make D reply with 4xx and to have Postfix invoke its back-off strategies. The downside is that changes to milter D would be required, which happens to be third-party software. It currently relies on the necessary data being already available when called. Hence my idea to introduce some form of transport that adds a long enough delay to ensure that the data is actually present when D is called. Still, I have asked the authors of milter D if they would even consider making any changes; an answer is pending. -Ralph
