How To Apply Email validation

[RuleRegularExpression("RuleRegularExpression for classname.propertyname", DefaultContexts.Save, @"^([\w-\.]+)@((\[[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.)|(([\w-]+\.)+))([a-zA-Z]{2,4}|[0-9]{1,3})(\]?)$", "It should be in given format")] [RuleRequiredField("RuleRequiredField for Company.PhoneNumber", DefaultContexts.Save, "Can Not be Empty you have to Give Phone Number")] [RuleRange("RuleRange for Payment.Rate", DefaultContexts.Save, 10, 20, "Enter with in range")] Here payment is a class and rate is property [RuleUniqueValue("RuleUniqueValue", DefaultContexts.Save, "RuleUniqueValue description")] [RuleRequiredField("RuleRequiredField for classname.propertyname ", DefaultContexts.Save, "Can Not Be Empty")] [RuleObjectExists("ClassName_ComplexValidationSettingsObject", DefaultContexts.Save, "CalculationTypes = '@CalculationTypes'AND Amount='@Amount' AND Schedule='@Schedule' AND IsActive='@IsActive'", MessageTemplateMustExist = "Objects with the same combination of the properties must not exist.", InvertResult = true, SkipNullOrEmptyValues = true, FoundObjectMessageFormat = "'{0}'", FoundObjectMessagesSeparator = ";")]