outlook for mac - wrong date on the sent items
Follow the steps mentioned below :


Create a new identity to remove database issues
Check your folder’s arrangement and system settings


To create a new user, the predefined path is :

Go to System Preferences --> Create a New User in Accounts.

Then Switch to the New User by logging out/in or you can try user Switching option.

If you still face this issue then problem exists into folders i.e. associated with Outlook Mac backup file.