What is an ideal way to return a status code or a complex object in C#?

I'm trying to figure out how best to deal with the following scenario. I have a server that receives messages, processes them, and then sends responses back to a client. I want to have the processing step return detailed information about the results of processing performed and an object in some cases.

I have code like the following:

public void HandleMessage(Connection conn, Packet packet) {
    var somedata = packet.Read();
    var result = Process(somedata);

    if (result == typeof(Message))
        SendA(result);

    if (result == typeof(MyObject))
        SendB(result, extraInfo);
}

public [what goes here] Process(object data) {
    if (validated)
        return data;
    else
        return Message.Failed;
}

What I want to do is create a separation of responsibilities.

• Receiver : parses data into meaningful objects
• Processor : acts upon parsed data and returns a status code or object.
• Sender : interprets returned data from a processor(s), constructs a packet, and sends this to the client.

What kind of design should I try to implement to achieve something like this?