Traveler - Signing Out of Your Device

You can sign out of your device by long-pressing the power button for 4 seconds. You will be prompted to sign out. 

This is a feature intended to allow for multiple writers to share a single device . Drafts linked to one Postbox account will not be visible when another Postbox account is signed in. You can check to see who is signed into a device by toggling the status screen to the Original Screen and viewing which email is below the date.