Administrative Contacts
Default Contact
If a Contact, Donor, or Participant is not an authenticated user, MinistryPlatform uses the information provided to try to find a unique match on the Contacts page. If it can't find a unique match, then the record is temporarily assigned to the Default Contact.
Regularly review records assigned to Default Contact and reassign them to the correct record. The most common way to manage reassignment is to use the Assign Donor Tool for Online Donations or the Assign Participant Tool for Events with public Event Registration.
Unassigned Contact
The Unassigned Contact is a dummy Contact, Participant, and Donor record that you can use as a placeholder when there is not enough information to assign to a real record. (The Unassigned Contact doesn't need to have a User record.)
Use the Unassigned Contact for records assigned to the Default Contact record that didn't provide enough information to actually create a new record. For example, Anne registers multiple other ladies for a woman's event using her email and phone for all of the Contacts and Participants she registered. You may assign those records to the Unassigned Contact record since you don't want to create new records with the incorrect data in your system. You can also use the Unassigned Contact for cash donations in envelopes that are illegible.
Reassigning to the Unassigned Contact record consequently removes the record from any Fix Default Records views.
Church Administrator Contact
The Church Administrator Contact is a dummy Contact used to send Platform notifications, attendance reminders, form submission notifications, and so on.
You should change the Church Administrator email address to one that the primary SPoC can check (it an be their personal inbox). The Church Administrator account is the fail-safe for the church if they accidentally lock themselves out.