public Message ReplyToConversation(Conversation conversation, User sender, User receiver, string messageText, string subject, string body) { Message retVal = null; if (sender != null) { //TODO - don't just check or null - throw ex or don't check at all if (conversation != null) { retVal = sender.WriteMessage(messageText); conversation.AddMessage(retVal); _emailService.SendMail(receiver.Email, subject, body); } } return retVal; }