How to access resource account in Outlook Web App (OWA) with FullAccess permissions
You have been given FullAccess permissions to a resource account and want to open it inside of Outlook Web App (OWA)
Step 1. In a web browser, visit Office 365
Step 2. Click the link 'Outlook Web App (OWA)'
Step 3. Input your EID and its password, then click the 'Sign In' button
Step 4. Click the person icon in the upper right corner
Step 5. Click 'Open another mailbox...'
Step 6. Type in firstname.lastname@example.org and click 'Search Directory'
Step 7. It should find the account, then click the 'Open' button