Having done a fresh install I need to set this up again. We could do with an up to date guide. This might encourage more people to use encryption and signing.
I already have a keyring, but others need to know how to do that. That should probably be a separate question. I use KGPG to manage my keys.
In Kmail I know you need to set the default signing and encryption keys on your Identity.
When I try to sign an email it complains that signing failed without asking for my pass-phrase. What am I missing? How should I configure cryptography in Kmail?