[Mailman-Developers] MIME footers

[Barry Warsaw]

On Feb 27, 2015, at 11:46 AM, Murray S. Kucherawy wrote:

>How absurd would it be to propose a flag for Mailman that would take your
>first case (non-MIME, or single-part text/plain) and convert it to a
>multipart/mixed with a child part of the original text/plain, and then
>apply the algorithm you have?

[...]
>
>What I'm worried about with such a design is the trivial text/plain
>message.  Obviously merely appending the footer destroys any hope of
>validating only the original content.  We'd have to entertain the idea that
>Mailman would make the simple message into a multipart/mixed + text/plain,
>then append the footer part and sign that; the verifier would drop the
>footer and then strip off the MIME to see if it can verify the original
>signature that way.  That seems like its easy to get wrong, though it's
>likely to be a very common case.

The biggest downside, and probably the main reason we append the footer text
in the text/plain-compatible-charset case is because of crappy MUAs.  I think
we *still* get complaints about the MIME composition not being rendered very
well.  Their MUAs will show them attachments without the message content they
actually care about.

I wish I could say "fix the MUAs" but that's probably been futile since the
day email was invented. ;)

That said, it's not a totally unreasonable suggestion.  I wonder if it makes
sense to have that be a user option (then, what's the default, what a standard
says, or whatever minimizes user complaints).

Cheers,
-Barry