We have a project to write an automated email client which is required to link reply messages sent back in response to its original message, what is the best method to provide this linkage? I am using Postfix (2.11) as my test bed.
For a simple example using Postfix and our application as the client sending will the Message-ID: outbound from my application message be retained as it passes through Postfix, unaltered arriving at the destination mailbox on the same Postfix server? Will a reply from the Destination mailbox using MS Outlook contain the unaltered original message ID in the In-Reply-To: field? Is there a mail server standard around Message-ID: / In-Reply-To: formatting that would support using Message-ID: and In-Reply-To: to form the original -> reply linkage? We have read many articles about other mail servers which alter the Message-ID: field outbound to mask the client identity somewhat (not reveal internal host names for example). Is there a list somewhere which talks about the Message-ID: integrity between Postfix and various platforms? Our end goal is to ensure that the originating mailbox gets a response that it can marry up to the reply in the event that more than one message has been sent to the destination and one or more replies received from that client.
