application/pkcs7 handling (receive not send)

[George Michaelson]

Sorry to awaken an old story from 2019, but I would love to know what
frobs to tweak, to be able to decode PKCS7 S/MIME encoded payload.

MH-E is (I think) breaking out of the classic NMH path to do this,
with the payload. So, I don't "see" a clean path in mhnshow
definitions to do this.

The fine mail archive terminates in 2019 with a discussion on how to
SEND SMIME pkcs7. I just want to read at this point.

I successfully imported my "own" work certificate via P12 -> Firefox
-> P12 (in another format) -> gpgsm --import (gpgsm is fussy about
what P12 "is" apparently)) so I have a .kbx now with this magic. And
some call out from emacs is finding it.

(getting MH-E working was this works bundle-of-joy. It actually went
smoother than I feared, and that includes getting "modern auth"
working with Outlook 365 backed inbound Mail via mbsync, but sending
is classic password AUTH LOGIN over SMTP/587 via msmtp)

all cluestick hits greatfully received.

-G