On 03/08/2012 12:04 PM, James Vasile wrote: > On Thu, 08 Mar 2012 11:37:09 -0500, Daniel Kahn Gillmor<dkg@fifthhorseman.net> wrote: >> Any ideas on how to approach this? > > Treat messages with the same ID but different hashes as different? Given that a message hash would include all headers, including Received: and other MTA-added stuff, i think that would remove all relevance of the Message-ID field. in particular, it seems like we would just be identifying messages by their digest. If you're willing to ignore the headers and just look at a digest of the body, that still doesn't provide any help for the common (legitimate) case of a message jointly-delivered to a mailing list and to a specific (already-subscribed) user. That user will get two copies of the message, and since most mailing lists modify the body of the message (usually by adding a footer section with mailing list info) their bodies will also have different digests. So i don't see how to make this suggestion work without giving up on Message-IDs as the identifier entirely (and therefore accepting many more spurious duplicates than users currently need to tolerate). Any other suggestions or ideas? --dkg