Outlook is disconnected after the machine is up for 2 days

"It is most likely because your authentication ticket with the domain has expired. Whenever you log in a new authentication ticket is generated which is valid for a certain period of time, and in this cause it seems to be 48 Hours.

Because your on a different domain this will only get renewed when you physically log in, whereas if the server and domain was the same, it will get renewed automatically."