code: public static Delivery newProgressMail(@NotNull Context ctx, CharSequence title, String suffix, boolean indeterminate){
          Delivery.Builder builder = new Delivery.Builder(ctx)
                  .setTitle(title)
                  .setStyle(new ProgressStyle.Builder(ctx)
                                  .setIndeterminate(indeterminate)
                                  .setCloseOnFinish(true)
                                  .setPercentageMode(false)
                                  .setSuffix(suffix)
                                  .build());
  
          // Override some defaults
          return builder.setCancelable(false)
                 .setCanceledOnTouchOutside(false)
                 .build();
      }
docs: Create a new ProgressDialog 'Mail' delivery to display
  
  @param ctx               the application context
  @param title             the dialog title
  @param suffix            the progress text suffix
  @param indeterminate     the progress indeterminate flag
  @return                  the new Delivery