public void Add(IEmailBussinessRule rule)
 {
     if (!_rules.Contains(rule))
     {
         _rules.Add(rule);
     }
 }
        public IBussinessRulesEvaluator WithRule(IEmailBussinessRule rule)
        {
            if (!_rules.Contains(rule))
            {
                _rules.Add(rule);
            }

            return(this);
        }