If you get Your Outlook data file cannot be configured error when opening Microsoft Outlook and your email account, see this post for the fixes.

Outlook Data File – The file C:\Users\<username>\AppData\Local\Microsoft\<username>\username.ost is in use and cannot be accessed. Close any application that is using this file, and then try again.

Check where each of your email accounts is delivering mail. After migration to Outlook 2010, sometimes the location is missing. You can check it from here: Click File/Account Settings.