Comment 16 for bug 15485

I was fighting with this problem, too.
I have KGpg installed to take care about my keys. The key management worked fine, but first I was not able to set where the gpg.conf is (see bug https://bugs.launchpad.net/ubuntu/+source/kdeutils/+bug/119263). Based on the often referred page http://kontact.kde.org/kmail/kmail-pgpmime-howto.php I have setup the startup script for gpg-agent.

Then KMail worked. In the meantime, I found a workaround for KGpg bug mentioned above. The next day, KMail stopped working again and it took me a lot of time to find out that gpg-agent is run twice - first KGpg and then with the startup script as recommended by kde.org. Then it was simple, I deleted the startup script and made sure KGpg always starts on login.

For end-user, this is quite complicated and confusing. As proposed by others, it would be great if installation of KGpg requires also pinentry-qt and gpg-agent and when the bug 119263 is solved, things should work out-of-the-box.