Hi,

I apologize for the delay in replying.

On 22 September 2019 at 23:50 CEST, Lars Ingebrigtsen <larsi@gnus.org> wrote:
>
> I'm not very familiar with how S/MIME works.
>
> How do you ask Message to send with S/MIME?  Using the `C-c C-m C s'
> command?

Yes.

> And how do you set up the S/MIME recipient stuff?

My config :

(setq mml-smime-use 'epg)
(setq mm-decrypt-option 'always)
(setq mm-verify-option 'always)
(setq gnus-buttonized-mime-types '("multipart/encrypted" "multipart/signed"))

Then use gpgsm to import your certificate (delivered by a certificate authority).

Hope it helps.

Best,
C.