Office 365 and Transport Agents

On an Exchange 2013 server I can create an smtpReceiveAgent transport agent to perform the task shown on this page, which is this c# code (VB code is also available on the webpage): -

using System;
using System.Collections.Generic;
using System.Text;
using Microsoft.Exchange.Data.Transport;
using Microsoft.Exchange.Data.Transport.Smtp;

namespace MyAgents
{
    public sealed class MyAgentFactory : SmtpReceiveAgentFactory
    {
        public override SmtpReceiveAgent CreateAgent(SmtpServer server)
        {
            return new MyAgent();
        }
    }
    public class MyAgent : SmtpReceiveAgent
    {
        public MyAgent()
        {
            this.OnEndOfData += new EndOfDataEventHandler(MyEndOfDataHandler);
        }
        private void MyEndOfDataHandler (ReceiveMessageEventSource source, EndOfDataEventArgs e)

        {
            // The following line appends text to the subject of the message that caused the event.
            e.MailItem.Message.Subject += " - this text appended by MyAgent";
        }
    }
}

How can I do something similar on my Office 365 Exchange implementation?

Thanks, Paul.