By default, instructors in a course will receive an email every time a student makes a Turnitin submission within Moodle. If you'd prefer not to receive these emails, you can adjust your settings to stop any emails. This is a Moodle-wide setting and will affect all of your courses.
To change your notification preferences, click on your name on the top right of any Moodle page → Preferences → User account → Notification Preferences. Scroll down to the sections for Turnitin Assignment and Turnitin plagiarism plugin and click each option to set them all to "Off" to prevent emails being sent whether you are online or offline.