I've had both 2011 Home & Student Office and the corresponding Outlook 2011 (14.4.9) installed and operating without incident a year now, until yesterday. Word & Excel both appear to function normally, but Outlook will no longer receive or send email which is of primary use and that is the problem here.

My machine is an Apple Mac Pro, 2009, OSX 10.8.5 (mountain lion), with 32GB of ram & 4 x 1TB Hard drives, all of which have at least 50% or more of capacity open on each of them. Internet access is via Time Warner Cable that goes through a router directly to the Mac Pro, with no other loads on it. The causal event, I believe, was a clean out operation, by me deleting old files, etc., thinking "what a good boy was I". It seems obvious to me, that I must have deleted something I shouldn't have. 

When trying to receive, the error message says authentication failed as shown in the screen shot below. When I looked at the email account user name & password information I saw that the password field was blank, which it should not have been, I think. I put the password back in, but there is no joy, I still get the same error message and nothing sends or receives. I have ThunderBird working now, but would like to get Outlook working again. Any help would be greatly appreciated.