Outlook 365 Does Not Open to Default Email Address

[cosrocket]

I have 4 email addresses that I use in Outlook 365. All of a sudden when I open Outlook it starts and opens the top email with one of my other email addresses, not my default email address. I checked under Account Settings and my default email address is checked so I don't get why this is happening. I did have to make a couple of changes under the View settings tab but I'm not sure what if anything I did is causing this to happen. Is there something else I can check to fix this issue? Thanks.