Mail Merge Connection Status window in GTK3 is fixed and cannot be moved which creates a problem with a lower monitor resolution, it cannot be closed. Also, it's startup position should be higher, so that it can be completely seen on lower resolution monitors.
Actually, problem is only if Details are expanded. Regardless, it should be able to be moved. How it looks normally can be seen in attachment 179314 [details].
The ui file is sw/uiconfig/swriter/ui/mmsendmails.ui and the cxx file is sw/source/ui/dbui/mmoutputtypepage.cxx