We have added a mechanism for Race Directors to mark addresses as “Undeliverable”. This is convenient for races who want to do physical mailers and want to save postage costs. You can do this by Editing a User (reach this from View participants -> Edit User):

In the View Participants, you will need to turn on this Hidden Field in the View Participants View options:

Then select the field doing a new query:

This will generate the report like this, which can be exported and sorted in a spreadsheet:
