Apparently, godaddy is sending invite access requests 'on behalf of' that account owners email. Problem is, the email still originates from godaddy.com, which then fails the DMARC spoofing policy. One way to resolve is to disable the 'Enable DMARC policy compliance check' under the options tab of Antispam Administration.

Running an older version (15.7.6885) of smartermail. Can incoming DMARC settings be modified in newer versions?

Thank you all!

Ben