status of S/MIME and interoperability?

Daiki Ueno ueno at
Tue Feb 2 10:26:17 CET 2016

Werner Koch <wk at> writes:

> On Sat, 30 Jan 2016 02:02, gdt at said:
>> I am using gnus/epg/gpgsm (emacs 24, gpgsm 2.0.29, on NetBSD 6 i386) to
>> do S/MIME.  Yes, I know why I should use OpenPGP instead, and the entire
> I have had problems with epg and S/MIME.  Without a real need to get
> this working I just ignore the problems.  I am still using Emacs 23,
> though.

It's not surprising; me too use S/MIME only occasionally to verify
emails from certain senders :-)

Greg Troxel <gdt at> writes:

> Sending, my impression is that users of Thunderbird and
> following can receive my encrypted messages, at least without large
> attachments.  But Outlook users appear not to be able to process
> encrypted messages from gnus/gpgsm.

For this particular interop issue, I am curious what is causing the
difference.  S/MIME encrypted messages are typically in the
enveloped-data format, which means that the encrypted content is simply
treated as an attachment.

If you have access to an MUA interoperable with Outlook, could you
compare the message structures for the success/failure cases?

Daiki Ueno

More information about the Gnupg-devel mailing list