Given the recent (offtopic) question about footers and multipart/alternate,
I wonder about just what is the correct way to attach a footer to weirdly
typed messages. Right now I take a really naive approach (which is
currently improper, but is just a start) and:
Stick the footer right in the body of a single-part, text/plain body.
This is what 1.94.x does.
Do _not_ stick the footer onto a single-part, anything else body.
This prevents the hosing of non-text parts.
Attach the footer as a separate part to a multipart body.
Now I see that the last rule is wrong; it should only be done to
multipart/mixed and not for anything else.
To do anything more would mean turning a single-part message into a
multipart one just for the footer, or would require that I encapsulate a
multipart/* as one part in a multipart/mixed. These churn my stomach, but
it may come to that when people ask why the footer isn't there in a
multipart/alternate. (It's not there because they didn't supply it in all
of the alternate forms. We can't just stick it in the text part and leave
it out of the HTML part.)