According to this upstream bug report, this is solved with the libsasl2-modules package greater that 2.1.19 or by installing the latest cyrus-sasl release: http://bugs.kde.org/show_bug.cgi?id=99632 Dapper currently has 2.1.19-1.7ubuntu5 of libsasl2-modules -- kmail vs. gssapi https://launchpad.net/malone/bugs/27084