When Xero is setup with ezyCollect, the first sync will bring across all customer contact details.
The "Primary Contact" will always be tagged to Receive All Communications in ezyCollect by default.
In addition to that, customer contacts that have the field "Include in emails" set to True in Xero, will also be tagged to Receive all Communications in ezyCollect.
Note: To tailor specific customer contacts to receive different automated communications in ezyCollect, please check our Customer Contact Tagging and Advanced Communication Workflow Settings.