Outlook and outlook.com two. Two separate windows.

[WPCentral Question]

Before I bought my Lumia 640, I was already on office 360. So I had an outlook.com mailbox and a microsoft account. Now I have two panes on the lumia--once for outlook.com and one for outlook. And my calendar on Lumia phone shows each event twice.

I want to delete one of the outlook windows and see that I can only delete the outlook.com window. Is that the correct thing to do to eliminate the problem?