Problem with Office365 on Outlook

So my company recently moved over to Office 365 plan for emails and we are using Office 2011 Outlook. everything works great but theres an annoying problem that Outlook always asked me for my login at least 3-4 times a day, before it would never asked me for my credentials, i would log in once and i never had to reenter my password again.

i havent search the forum about this topic yet, so please don't flame me, i will do some research when i get home.

thanks,