KMail, OpenPGP plug-in not specified

[Rob Andrews]

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I've got a bit of a PEBCAK issue here, since I'm pretty new to actually using 
secure communications in a real way. I'm using GnuPG 1.2.3 with KMail, and as 
I sift through incoming messages, some begin with the following:

> Message was signed with unknown key.
> The validity of the signature cannot be verified.
> Problem: OpenPGP plug-in was not specified.
> Use the 'Settings->Configure KMail->Security' dialog to specify the plug-in
> or ask your system administrator to do that for you.

Other messages will begin with the first two lines (except that they will 
actually list the unknown key in question), and not cite a plug-in problem.

I don't know how much of my situation is KMail ignorance, how much is 
encryption ignorance, and how much is general ignorance, so I'm asking here. 
At first glance, I assume this is one of those situations in which the answer 
to my question is probably well-documented somewhere, but I just don't know 
where to look off-hand.

regards
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