Version: 1.7.1 (using KDE KDE 3.3.1) Installed from: Debian testing/unstable Packages OS: Linux When this happens and I try to send an email, I get an error that tells me that no signing keys are available. Trying to edit the relevant identity afterwards, I get a box that tells me "General Error Could not retrieve signing keys from backend." Restarting Kmail (or rather, Kontact) usually fixes the problem.
I have this problem as well. When this happens, kmail is also unable to verify any signatures. It is really annoying having to restart kontact twice a day or so...
Experimented a bit and I can now confirm that this only happens when Kmail is started from within Kontact.
Hasn't happened in a year or so.