So this tells me that existing mail software doesn't try very hard to recover signatures from modified messages, even for simple changes that don't need any guessing or heuristics to undo.My client found the signature, otherwise it would not have commented on its validity. It just wasn't able to verify it.
Hmmn. How does it like the copy of this message sent to you directly? The signature was definitely good on the way out.
I think the long term solution would be for mailing list software to stop mucking around with the message body, and for MUAs to work better at exposing meta data added by lists (like the list-unsubscribe header).
Actually, I think the long term solution is for people to stop pretending there is a problem. Can you describe the operational problems you're experiencing here? "Broken signatures" is a fact, not a problem. Mailing lists have worked quite well for 40 years with no signatures at all, making all sorts of random changes to the mail, so it has to be something more than that.
Also, if you're suggesting changes to list software, please explain why they would have greater benefits than the obvious and simple one to have lists add their own signature on the way out.
Regards, John Levine, jo...@iecc.com, Primary Perpetrator of "The Internet for Dummies", Please consider the environment before reading this e-mail. http://jl.ly
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