RE: Export list of all updated contacts email addresses
Hi partner,
There is no OOB way to do this.
You could refer to my thoughts.
1.Create a datetime field on the contact form named "EmailModifiedDate".
2.Add a js function on the email field "onchange" event, when the email update, then set the current datetime as value to "EmailModifiedDate".
function getEmailModifyDate(executionContext){
var formContext = executionContext.getFormContext();
var today=new Date();
formContext.getAttribute("EmailModifiedDate").setValue(today);
}
3.Then you just need to filter contact records with conditions "created on" and "EmailModifiedDate" in last 7 days in advanced find.

Hope it helps.
Best Regards,
Leo