I'm in the process of setting up gpg in kmail. Signature works and I was testing encryption with the adele robot of http://www.gnupp.de/ (german site). They provide a robotic service which sent me a mail with its public key in the body of the mail itself, not as an attachment.

Thunderbird can import keys like these. How is it done in kmail?

I'm not certain this is what you want, but, in Kmail Settings -> Configure Kmail, click on the Security icon. Under the Reading tab, down at the bottom of the page, there is an option to "Automatically import keys and certificate".

Okay, I'll test that over the weekend and report back.

In the meantime I found a workaround: run "Kgpg", it has a menu to handle keys, click on "import" and a popup will appear, asking among other things either for a file name or to import from the clipboard. Bingo.

I copied the key to the clipboard out of the mail starting with "-----BEGIN PGP SIGNATURE-----" up to and including "-----END PGP SIGNATURE-----", checked this option and clicked okay. Back in Kmail the new key was there and ready to use.

I'd prefer a direct way in Kmail, though.

That is already checked. Seems that it means just keys / certificates in appended files. I want to import from the body of a mail just like thunderbird can do. Thanks for your input all the same.