It can be anything! An apex, subdomain, or even a URL.
Results formspim.ext.azure.com.office.o365rp.fcc.myshn.eu
www.mspim.ext.azure.com.office.o365rp.fcc.myshn.euext.azure.com.office.o365rp.fcc.myshn.euazure.com.office.o365rp.fcc.myshn.eucom.office.o365rp.fcc.myshn.euoffice.o365rp.fcc.myshn.euo365rp.fcc.myshn.eufcc.myshn.eumyshn.eueu