I have a similar problem (on 11.04, KDE updated through the backport PPA). It also devoured my emails. When I turned on the spam/anti-virus filters, it deleted them from the IMAP server (my email provider is GMX), ran the checks, then tried to upload them back to the server and I got a similar message; "could not upload the message ..." "unexpected end of data." The net result was that the email was deleted, and was not present either on my computer or the server. I lost a few days of emails, until I found a work-around (firstly using thunderbird to read email, then switching off the spam/anti-virus filters on kmail).
dpkg -l | grep kdepim ii kdepim 4:4.4.10-0ubuntu4 Personal Information Management apps from the official KDE release ii kdepim-groupware 4:4.4.10-0ubuntu4 KDE PIM Groupware plugins ii kdepim-kresources 4:4.4.10-0ubuntu4 KDE PIM resource plugins ii kdepim-runtime 4:4.4.10-0ubuntu2 Runtime components for akonadi-kde ii kdepim-strigi-plugins 4:4.4.10-0ubuntu4 PIM file format plugins for Strigi Desktop Search ii kdepim-wizards 4:4.4.10-0ubuntu4 KDE server configuration wizards ii kdepimlibs-kio-plugins 4:4.7.0-0ubuntu1~natty1~ppa1 kio slaves used by KDE PIM applications ii libkdepim4 4:4.4.10-0ubuntu4 KDE PIM library -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/819676 Title: Missing required argument to Append command To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/kdepim/+bug/819676/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs