Under Construction!!!
Step 1 - In the Outlook desktop app, click 'File'
Step 2 - Use the 'From' drop-down menu to select 'Other Email Address...'Choose Account Settings, then select Account Settings from the menu.
Step 3 - Click the 'FromSelect the Email tab. Make sure your Exchange email account is selected, then choose 'Change...'option to expand the next menu
Step 4 - Click the drop-down arrow to select 'Global Address List'Select 'More Settings'
Step 5 - Type the name of the Shared Exchange Mailbox in the Search barClick the 'Advanced' tab, then click 'Add'.
Step 6 - Select the Shared Exchange Mailbox Type the name of the shared mailbox you want to add, then click 'OK'.
Step 7 - Click 'OK'
Step 8 - The name of the Shared Exchange Mailbox will now be available when composing a New Email message in Outlook
Choose Next > Finish > Close.