Emails sent from ITscope in your name will be sent on behalf of your user email address.
First of all, this is useful because the emails look more professional if your email address is included. However, this very feature can also be used by attackers to impersonate the sender of the email.
For this reason, the Sender Policy Framework (SPF for short) and DKIM were introduced to prevent the forgery of an email’s sender address. Strictly speaking, this is what we do, so the email is rejected by the recipient (or ends up in their spam folder) because our mail servers are not authorised to ‘use’ your domain. By setting up your domain and adding the SPF and DKIM DNS TXT records, we are then authorised to use your domain in the eyes of receiving mail servers:
For more information on SPF entries, see https://en.wikipedia.org/wiki/Sender_Policy_Framework and www.openspf.org.