"Could not start process pop3s."

I find out this is a different kind of bug. Apparently the kmail package does not depend on the kdebase-kio-plugins package, and thus it can only read imap mails, not pop mails, unless such kio package is installed separately.

does in feisty.

sarah@LongPointyStick:~$ show kmail | grep kdebase-kio-plugins
Depends: kdelibs4c2a (>= 4:3.5.5-1), libart-2.0-2 (>= 2.3.16), libaudio2, libc6 (>= 2.5-0ubuntu1), libfontconfig1 (>= 2.4.0), libfreetype6 (>= 2.2), libgcc1 (>= 1:4.1.1-31), libice6 (>= 1:1.0.0), libidn11 (>= 0.5.18), libjpeg62, libkcal2b (>= 4:3.5.3), libkdepim1a (>= 4:3.5.3), libkleopatra1 (>= 4:3.5.3), libkmime2 (>= 4:3.5.3), libkpimidentities1 (>= 4:3.5.3), libksieve0 (>= 4:3.5.3), libmimelib1c2a (>= 4:3.5.3), libpng12-0 (>= 1.2.13-4), libqt3-mt (>= 3:3.3.7), libsm6, libstdc++6 (>= 4.1.1-31), libx11-6, libxcursor1 (>> 1.1.2), libxext6, libxft2 (>> 2.1.1), libxi6, libxinerama1, libxrandr2, libxrender1, libxt6, zlib1g (>= 1:1.2.1), perl, kdepim-kio-plugins, kdebase-kio-plugins
Recommends: kdepim-kio-plugins, kdebase-kio-plugins, procmail
 mbox files, and/or kdebase-kio-plugins if you want to use POP3.
Depends: kdelibs4c2a (>= 4:3.5.5-1), libart-2.0-2 (>= 2.3.16), libaudio2, libc6 (>= 2.5-0ubuntu1), libfontconfig1 (>= 2.4.0), libfreetype6 (>= 2.2), libgcc1 (>= 1:4.1.1-21ubuntu1), libice6 (>= 1:1.0.0), libidn11 (>= 0.5.18), libjpeg62, libkcal2b (>= 4:3.5.3), libkdepim1a (>= 4:3.5.3), libkleopatra1 (>= 4:3.5.3), libkmime2 (>= 4:3.5.3), libkpimidentities1 (>= 4:3.5.3), libksieve0 (>= 4:3.5.3), libmimelib1c2a (>= 4:3.5.3), libpng12-0 (>= 1.2.13-4), libqt3-mt (>= 3:3.3.7), libsm6, libstdc++6 (>= 4.1.1-21ubuntu1), libx11-6, libxcursor1 (>> 1.1.2), libxext6, libxft2 (>> 2.1.1), libxi6, libxinerama1, libxrandr2, libxrender1, libxt6, zlib1g (>= 1:1.2.1), perl, kdepim-kio-plugins, kdebase-kio-plugins
Recommends: kdepim-kio-plugins, kdebase-kio-plugins, procmail
 mbox files, and/or kdebase-kio-plugins if you want to use POP3.