Step 1: Flag the email in the inbox as normal.
Step 2: Once the email is flagged. With the mouse, press and hold the Right-click option and drag it down to the tasks icon on the bottom left (logo with the tick).
Step 3: You will see a pop up of 3 options, click the top option which is ‘Copy Here as Task with Text’.
Step 4: Set up the task with whatever deadlines you want. Once finished click ‘Save & Close’ on the top left.
Step 5: Click on the Task icon now to open up the tasks page.
Step 6: The task by Default will be saved under your own email address. To move it into the shared mailbox address, just left click and drag it towards the shared mailbox name. This will remove it from your mailbox task list and add it to the shared mailbox task list.