Enum DeliveryNotificationOptions Path C++ Link System.Net.Mail.DeliveryNotificationOptions, System underlying int32 System Values 5 NameValueHex None00x00OnSuccess10x01OnFailure20x02Delay40x04Never1342177280x8000000 Used by 1types with a member, parameter or interface of this type MailMessage // System.Net.Mail.DeliveryNotificationOptions, System enum class DeliveryNotificationOptions : int32 { None = 0, OnSuccess = 1, OnFailure = 2, Delay = 4, Never = 134217728, };