Step 1: Click your profile picture in the top right
Step 2: Click 'open another mailbox'
Step 3: Enter the email you wish to open. (NOTE: You need to have permissions set to open another mailbox)
Step 4: Select the email you wish to open
Step 5: Then click 'Open'
Step 6: You have now open another mailbox. You can check the mailbox your in by looking at the email address in the URL.
