Hello ,Few questions before I can answer your question.1> Is the product used ACS or Campaign V6/V72>. Sub-domain delegation to Adobe is a complete process which needs to be completed by Adobe if it is Hosted by Adobe Managed Services. The details of the step are given here : https://docs.campaign.adobe.com/doc/AC6.1/en/Technotes/AdobeCampaign_Deliverability_Sub_Domain_Delegation.pdfIn short , if you have got the sub-domain configured you need to point the name server records to Adobe and then o...