Create a new SmartList and choose the option Create a new SmartList based on an existing one then choose the All Donors SmartList from the dropdown menu. If you also want to include Affiliate Donors, you will want to instead choose the All Donors and Affiliate Donors SmartList.
Click Refine next to the criteria set.
Click Append More.
Click on the click here to select a criteria category option. Choose Phone/Email Info and then choose Partial Email. Enter in *.* in that field.
Click on the blue Customize link (located on the right about the results list). Here you can then check the boxes of the fields you would like displayed including Email.