mx_unlock_file (ctx->path, fileno (ctx->fp));
mx_unlock_file (ctx->path, fileno (ctx->fp), 1);
void mbox_unlock_mailbox (CONTEXT *ctx){  if (ctx->locked)  {    fflush (ctx->fp);    mx_unlock_file (ctx->path, fileno (ctx->fp));    ctx->locked = 0;  }}