I have Outlook 2011 on my MacBook Air, I was checking my mails, then I closed the screen, then 10 minutes later  I reopened the screen to check my mails

and then all my folders, contacts and account on outlook disappeared.

So, I re entered my account in the setting of outlook, and only the new mails reappeared. All my folders with the mails inside disappeared, so did my contacts.

Can someone help me recover all my mails back.

Thank you very much.