If you drop Linux I am sure you can use outlook. I use a Gnome
and no matter how ppl keep repeating the "you can use KDE apps" it does
not work. Using KDE apps on a Gnome Desktop is like using a wine outlook
on a Linux desktop, it works but there are zillion little things like
cut and paste,
Cut&paste is completely compatible between KDE and GNOME apps and has been for
a long time now! The Qt clipboard bug where it mixed up PRIMARY (selection) and
CLIPBOARD was fixed ages ago.
default file browser, default web browser,
Run kcontrol and you can set your file associations. Getting Kontact to run
your GNOME applications when you open a file or URL in it is not hard. The
default browser for KDE apps is the setting for "text/html".
system settings etc. that all are different.
Just set them to the same thing. KDE is very flexible, it's possible to get it
to match the GNOME configuration very closely.