Open the control panel, make sure it is in classic view. Open the mail icon and click the data files button. Remove the data file that is causing the problem. Re-open outlook and it should open for you. If this is a .pst profile you may need to repair the .pst using scanpst. Is this a .pst account or do you had an archive file open on your folder list? Is this an exchange account you are connecting to by MAPI?