problems recognising gpg public keys

[Josh Robinson <jmr59@hermes.cam.ac.uk>]

i'm running Evolution 1.45 on KDE 3.1.4, with a recent (i think: i
downloaded it a couple of weeks ago) version of GnuPG. although i have
no problem signing messages, whenever i click on anyone else's
signature, i get the following error message :

>         This message is digitally signed but can not be proven to be
>         authentic.
>         
>         gpg: armor header: Version: GnuPG v1.2.3 (GNU/Linux)
>         gpg: Signature made Sun Dec 21 09:27:19 2003 GMT using DSA key
>         ID A75603D7
>         gpg: Can't check signature: public key not found

any advice: are there any servers i should be using? and how do i
configure GnuPG to look for public keyrings on different servers?

all best,

josh

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