When I go to my account settings and Amount to Synchronize, my options are only One day, Three days, One week, Two weeks or One month. Therefore, it will only sync emails that are less than 30 days old in my Outlook inbox.
I'm not really familiar with the stock app but you might need an app that gives you that option. I use Touchdown and can specify much more than 30 days. Not sure what the limit is for Touchdown. There are other email apps that support Exchange.
