This option allows creating a list of numbers that will be omitted in the outgoing campaign. Remember that for outgoing campaigns it is required to import a CSV file with the phone numbers to call. The Do not Call List is the list of numbers that will not be called although they are included in the imported CSV file.
You can add the restricted phone numbers manually or import them from a .csv file. It is important that after you add the numbers, click on the "Apply" button and check the status column that should be shown as "Active".
To remove a phone number just select the number by clicking on the checkbox and click on "Remove" button.