iPhone Email Help

Hi guys,

So I have my Outlook.com email account synced with my iPhone and it's set to only show 1 weeks worth of email, this is fine however I would like all of my "flagged" emails to show all of the time..even when they are older than 1 week, at the moment only flagged emails which are less than a week old are synced to my phone which is a little annoying. Is there anyway to make sure all my flagged emails are always there or do the settings need to be changed to make all emails available regardless of when they were received?

Thanks :)