On Thu, May 26, 2016 at 02:25:13PM -0600, Joel Beckham wrote: > I'm working towards p=reject on bombbomb.com and found that Securence / > usinternet.com (A forwarder) gets a measurable percentage of our mail and > modifies the message-id in the process.
There's the problem. They should not be doing so. It's clearly against the meaning/intent of RFC 5322, Section 3.6.4, which reads in part: The "Message-ID:" field provides a unique message identifier that refers to a particular version of a particular message. The uniqueness of the message identifier is guaranteed by the host that generates it (see below). and Note: There are many instances when messages are "changed", but those changes do not constitute a new instantiation of that message, and therefore the message would not get a new message identifier. For example, when messages are introduced into the transport system, they are often prepended with additional header fields such as trace fields (described in section 3.6.7) and resent fields (described in section 3.6.6). The addition of such header fields does not change the identity of the message and therefore the original "Message-ID:" field is retained. Forwarding a message changes it slightly but clearly does not constitute a new instantiation of the message, therefore the Message-ID should not be modified. It's also a bad idea operationally, as it will break things like loop detection, it will complicate problem diagnosis, and it will break anti-spam/anti-abuse mechanisms that rely on Message-ID. ---rsk _______________________________________________ mailop mailing list mailop@mailop.org https://chilli.nosignal.org/cgi-bin/mailman/listinfo/mailop