Chris Owen wrote: > On Jun 14, 2009, at 8:10 PM, Bill Landry wrote: > >>> Mailman has specific functionality to remove signature headers so >>> that the message can be resigned as it's sent out. > >> If that happens then the message is no longer signed by the original >> sender, but rather by the mailing list. Probably not a big deal for a >> mailing list, but would be in any person-to-person communications. > > > Why would someone wanting person-to-person communications send mail > through Mailman?
[replying back to the list for the benefit of others following this thread] They wouldn't. I was simply trying to illustrate a point that removing and resigning a message on a mailing list probably is not a big deal. But if, for example, a receiving MTA were to add some kind of footer to a signed message in a person-to-person communication (not a mailing list communication), then that would effectively render the DK and/or DKIM signatures invalid, as the message content would have changed. The same is true if a mailing list adds a footer to a message and does not remove the original DK and DKIM signatures, as the list recipients would receive the message with invalid signatures, and SA would report them as invalid. Bill
