One of our customers has asked us to implement sending from their root domain (company.com) rather than the SAP subdomain (send.company.com). I've explained (until I'm blue in the face) that you can't do this — well, you can but you shouldn't — but they are insistent that it's possible. That is, they believe they can simply add TXT records to their DNS for DMARC, DKIM and SPF.
Technically, they are right, but I believe the consideration is related to processing spam complaints through the "feedback loop" which I believe sends a Abuse Reporting Format (ARF) formatted email to the abuse@ (or postmaster@?) username and domain that is used to send the email, for example, [email protected]. That is why Marketing Cloud includes an MX record for the root (@) SAP domain in its DNS records, as it needs to receive these spam complaint emails. If it was possible to send an email from Marketing Cloud using the root domain, then the company mail server would have no way of forwarding the complaint to Marketing Cloud.
I wanted to validate my assumptions here. We opened a support ticket and Salesforce explained that we simply just need to register the root domain in From Address Management to send from it, which (as you hopefully know) is incorrect and terrible advice. It has been pointed out that Salesforce send emails from Marketing Cloud to customers using their root domain (salesforce.com), but I assume this is an exception and they can only do this because they, well, are Salesforce, and have a mechanism to route feedback loop messages to the platform.
Is my understanding correct? Has anyone actually configured the platform to send emails from their root domain?