Mutt/GnuPG-Outlook-plugin diffs / Support for Microsoft's .epf, .pfx, .p12 ?

gabriel rosenkoetter gr at
Thu Feb 12 14:06:02 CET 2004

On Thu, Feb 12, 2004 at 01:37:21PM -0500, Luis R. Rodriguez wrote:
> When I use mutt and sign an e-mail and send it to my outlook inbox,
> Outlook seems to detect it is a signed e-mail and flags this by showing
> a "signed" icon. I also find an attached .dat file. I notice the headers
> show some relevant info which may flag this.

That's a PGP/MIME-signed email, which mutt produces by default.

See and

Outlook can recognize PGP/MIME messages as being cryptographically
verifiable, though it can't cryptographically verify them. (Outlook,
as of maybe 2000 or so--the version number, not the year--supports
S/MIME natively. I don't believe it does not nor will it probably
ever support PGP/MIME natively: Microsoft is heavily behind
third-party certificate systems rather than PKI systems.)

> When I use the GnuPG plugin on Outlook and e-mail myself, I don't get 
> this "flag" or icon on my e-mail, nor any attached document or even any
> special headers.
> What gives?

The Outlook plugin you're using is only capable of producing
clear-signed messages.

> I notice that the file types it allows by defaut are :
> Security Information (*.epf, *.pfx, *.p12)

Those are the filename extensions. They say little or nothing about
the file types to anyone who doesn't use Windows.

> Are these "secret" keys in a *special* format? I exported my gpg
> key and tried to import it using this import utility and it failed.

Those are S/MIME certificates, probably, since that's all Outlook
supports natively.

gabriel rosenkoetter
gr at
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