+(D) add_files_recursive, pass 1: explicitly ignoring ${MAIL_DIR}/.ignored_hidden_file
+(D) add_files_recursive, pass 1: explicitly ignoring ${MAIL_DIR}/ignored_file
+(D) add_files_recursive, pass 1: explicitly ignoring ${MAIL_DIR}/one/ignored_file
+(D) add_files_recursive, pass 1: explicitly ignoring ${MAIL_DIR}/one/two/ignored_file