Hi Ajeeth, my name is Neil, I'm an independent adviser and Outlook user like you.
I'll be happy to answer your question. You have your view settings set to "Single". This is easy to rectify.
Simply follow these quick steps:
In Outlook, click on the View menu.
Then on the Ribbon below, look to the left and click on the "Change View" button.
Then click on Compact.
This will restore your View to what it was like before, and is the default view in Outlook that you're used to.
I hope this helps!
Kindest regards,
Neil