Using New Outlook on Windows for personal email, calendar, and contact management
Dear IT_Tech_886,
Good day! Thank you for posting to Microsoft Community. We are happy to assist you.
As per the description you have shared, we understand that you want to add permission to a shared mailbox using the New Outlook.
I'm sorry to inform you that the new Outlook does not currently support add permission to the shared mailbox. We do understand your concern here and we apologize if we are not able to meet your requirements at the moment. However, thank you for bringing this to our forum, your concern is very meaningful and reasonable. So, since the New Outlook for windows is still under active development, we will surely raise your concern to our Product Development Team and hopefully this can be included in the future updates. You can also provide your valuable suggestion to Our product development team via in-app feedback site, you can refer to Contact support and provide feedback within the new Outlook for Windows - Microsoft Support. Microsoft is constantly working on improving their products and adding new features, so it's possible that macros may be added in the future. In the meantime, you can continue to use the current version of Outlook (Classic Outlook) or Outlook on the web that supports add permission to the shared mailbox.
Thank you for your precious time, valuable insight and understanding. For other questions, feel free to add your post in the Microsoft Community team.
Stay safe and healthy. Have a good day!
Sincerely,
Libeamlak | Microsoft Community Moderator