Version:           4.3.3 (using KDE 4.3.3)
OS:                Other
Installed from:    Ubuntu Packages

The error output is as follows:

Application: KMail (kmail), signal SIGSEGV
[Current thread is 0 (LWP 8612)]

Thread 3 (Thread 0xb1a63b90 (LWP 8619)):
#0  0xb7f77430 in __kernel_vsyscall ()
#1  0xb5bb87b1 in select () from /lib/tls/i686/cmov/libc.so.6
#2  0xb5e8c380 in ?? () from /usr/lib/libQtCore.so.4
#3  0xb5dba96e in ?? () from /usr/lib/libQtCore.so.4
#4  0xb4fed4ff in start_thread () from /lib/tls/i686/cmov/libpthread.so.0
#5  0xb5bc049e in clone () from /lib/tls/i686/cmov/libc.so.6

Thread 2 (Thread 0xabc07b90 (LWP 8835)):
#0  0xb7f77430 in __kernel_vsyscall ()
#1  0xb4ff10e5 in pthread_cond_wait@@GLIBC_2.3.2 () from /lib/tls/i686/cmov/libpthread.so.0
#2  0xb5bcf2ed in pthread_cond_wait () from /lib/tls/i686/cmov/libc.so.6
#3  0xb5dbb9b2 in QWaitCondition::wait () from /usr/lib/libQtCore.so.4
#4  0xb6acd152 in ?? () from /usr/lib/libQtNetwork.so.4
#5  0xb5dba96e in ?? () from /usr/lib/libQtCore.so.4
#6  0xb4fed4ff in start_thread () from /lib/tls/i686/cmov/libpthread.so.0
#7  0xb5bc049e in clone () from /lib/tls/i686/cmov/libc.so.6

Thread 1 (Thread 0xb3be3b40 (LWP 8612)):
[KCrash Handler]
#6  0xb5ec4b1b in QMetaObject::activate () from /usr/lib/libQtCore.so.4
#7  0xb5ec5932 in QMetaObject::activate () from /usr/lib/libQtCore.so.4
#8  0xb6ae7103 in QAbstractSocket::error () from /usr/lib/libQtNetwork.so.4
#9  0xb6aea37b in ?? () from /usr/lib/libQtNetwork.so.4
#10 0xb6aee390 in QAbstractSocket::qt_metacall () from /usr/lib/libQtNetwork.so.4
#11 0xb6b15d02 in QTcpSocket::qt_metacall () from /usr/lib/libQtNetwork.so.4
#12 0xb5ebd8fb in QMetaCallEvent::placeMetaCall () from /usr/lib/libQtCore.so.4
#13 0xb5ebf3a0 in QObject::event () from /usr/lib/libQtCore.so.4
#14 0xb615be9c in QApplicationPrivate::notify_helper () from /usr/lib/libQtGui.so.4
#15 0xb616419e in QApplication::notify () from /usr/lib/libQtGui.so.4
#16 0xb7db294d in KApplication::notify () from /usr/lib/libkdeui.so.5
#17 0xb5eaea3b in QCoreApplication::notifyInternal () from /usr/lib/libQtCore.so.4
#18 0xb5eaf695 in QCoreApplicationPrivate::sendPostedEvents () from /usr/lib/libQtCore.so.4
#19 0xb5eaf88d in QCoreApplication::sendPostedEvents () from /usr/lib/libQtCore.so.4
#20 0xb5eda7ef in ?? () from /usr/lib/libQtCore.so.4
#21 0xb42e5b88 in g_main_context_dispatch () from /usr/lib/libglib-2.0.so.0
#22 0xb42e90eb in ?? () from /usr/lib/libglib-2.0.so.0
#23 0xb42e9268 in g_main_context_iteration () from /usr/lib/libglib-2.0.so.0
#24 0xb5eda438 in QEventDispatcherGlib::processEvents () from /usr/lib/libQtCore.so.4
#25 0xb61fd365 in ?? () from /usr/lib/libQtGui.so.4
#26 0xb5ead06a in QEventLoop::processEvents () from /usr/lib/libQtCore.so.4
#27 0xb5ead4aa in QEventLoop::exec () from /usr/lib/libQtCore.so.4
#28 0xb6676403 in QDialog::exec () from /usr/lib/libQtGui.so.4
#29 0xb767d6f5 in ?? () from /usr/lib/libkmailprivate.so.4
#30 0xb7272cd4 in ?? () from /usr/lib/libkmailprivate.so.4
#31 0xb74959e1 in KMKernel::openReader () from /usr/lib/libkmailprivate.so.4
#32 0xb7497754 in KMKernel::action () from /usr/lib/libkmailprivate.so.4
#33 0xb74989ff in KMKernel::handleCommandLine () from /usr/lib/libkmailprivate.so.4
#34 0x0804af8d in _start ()

I feel this should be adequate to find the problem for those of us into code... In short I have followed Yahoo's instructions to the letter and still cannot send or retrieve e-mail. Thank you for your time and efforts.