Dear Maintainer,

   * What led up to the situation?

Screensaver was enabled, and I received new mail. I was at desk but inactive on machine.
My new mail information showed on the screen, allowing passerbys or overshoulder watchers to see my private mails.

   * What exactly did you do (or not do) that was effective (or
     ineffective)?

Enabled a password on my screensaver to prevent unauthorized access to my machine and information.

   * What was the outcome of this action?

Non-authorized persons can see my mail subjects / correspondents / etc.

   * What outcome did you expect instead?

Icedove to not draw over the screensaver.