Sometimes ITSG will ask you to forward an email as an attachment for troubleshooting purposes.
This article will guide you through the process in Outlook 2016 for Mac
Right click on the email in question in your inbox, choose "Forward Special", then "As Attachment".
Update the subject to be relevant to the request (e.g. "Received spam email" or something similar). Fill in a quick message so ITSG know what this is about. Make sure you can see the attachment underneath the subject. Then, send the email!