And ultimately they have a lot more important things to be doing then learning a different email client than the one they use at their desk on earth. This is an email client on a laptop, not a navigation system.
The mission of the astronauts on board is to test the damn Orion spacecraft in preparation for a human landing on the moon.
> NASA flight controller and instructor Robert Frost explained the reasoning plainly in a post on Quora (via Forbes). “A Windows laptop is used for the same reasons a majority of people that use computers use Windows. It is a system that people are already familiar with. Why make them learn a new operating system,” he reportedly wrote.
Maybe he should have designed the rest of the controls to look like the cockpit of 2003 Toyota Camry. It is a system that people are already familiar with. And actually reliable.