Same as the rest, this option does not exist in the new outlook. I understand this new app is basically a ported webapp version of the online one; but the fact that this is a desktop experience should par with a expected desktop behaviour IMO. Let us know where we can submit a feature request to enable a "Doble Click to open items". I think this way we can eventually blend both options for end users to select and personalize their experience.
Hello Abhay,
Welcome to the Microsoft Community. I am a Microsoft user like you, I hope you are doing well.
To disable a single click to open email in New Outlook, you must change the reading pane settings in your Outlook options. Here are the steps you can follow:
• Sign in to your Outlook account using your email address and password.
• At the top of the page, select Settings and choose View all Outlook settings.
• In the Settings pan, go to Layout and select the Reading pane under Maile.
• Under Mark as read, uncheck the option Single click to open items.
• Click Save to apply the changes.
I hope this helps you disable a single click to open the email in New Outlook.