{ config, options, lib, ... }: { ###### interface options = { services.mail = { sendmailSetuidWrapper = lib.mkOption { type = lib.types.nullOr options.security.wrappers.type.nestedTypes.elemType; default = null; internal = true; description = '' Configuration for the sendmail setuid wapper. ''; }; }; }; ###### implementation config = lib.mkIf (config.services.mail.sendmailSetuidWrapper != null) { security.wrappers.sendmail = config.services.mail.sendmailSetuidWrapper; }; }