paludis -pi kmail gives:
Building target list...
Building dependency list...paludis@1174133677: [WARNING] In program paludis -pi kmail:
  ... When performing install action from command line:
  ... When executing install task:
  ... When adding PackageDepSpec 'kde-base/kmail':
  ... When adding package 'kde-base/kmail-3.5.5-r1::gentoo':
  ... When adding build dependencies as pre dependencies:
  ... When adding PackageDepSpec '~|~|~|~|~|~kde-base/libksieve-3.5.5,3.5.4,3.5.3,3.5.2,3.5.1,3.5.0':
  ... When adding installed package 'kde-base/libksieve-3.5.0::installed':
  ... When adding run dependencies as post dependencies:
  ... When adding PackageDepSpec '~kde-base/kde-env-3':
  ... When adding package 'kde-base/kde-env-3-r4::gentoo':
  ... Dropping run dependencies to post dependencies because of exception 'Block: >=kde-base/kdelibs-3.5.4-r2' (paludis::BlockError)
paludis@1174133677: [WARNING] In program paludis -pi kmail:
  ... When performing install action from command line:
  ... When executing install task:
  ... When adding PackageDepSpec 'kde-base/kmail':
  ... When adding package 'kde-base/kmail-3.5.5-r1::gentoo':
  ... When adding build dependencies as pre dependencies:
  ... When adding PackageDepSpec '~|~|~|~|~|~kde-base/libksieve-3.5.5,3.5.4,3.5.3,3.5.2,3.5.1,3.5.0':
  ... When adding installed package 'kde-base/libksieve-3.5.0::installed':
  ... Ignoring run dependencies due to exception 'Block: >=kde-base/kdelibs-3.5.4-r2' (paludis::BlockError)