#define topt_use_bdat 0x100 /* prepend chunks with RFC3030 BDAT header */
#define topt_output_string 0x200 /* create string rather than write to fd */
#define topt_continuation 0x400 /* do not reset buffer */
+#define topt_not_socket 0x800 /* cannot do socket-only syscalls */
/* Options for smtp_write_command */