class Program
{
    static void Main(string[] args)
    {
        var server = new SmtpServer(new ServerSettings()
        {
            Endpoint = IPAddress.Parse("127.0.0.1"),
            ServiceName = "ExampleService",
            ServiceDomain = "mx.example.org"
        });

        server.AddPluginAsync(new SpamhausPlugin()).Wait();
        server.AddPluginAsync(new ExampleMailProcessor()).Wait();

        server.Run();
    }
}

class ExampleMailProcessor : IMailProcessor
{
    public async Task<MailProcessorResult> ProcessAsync(string from, string[] rcpt, Stream data)
    {
        var stringData = await new StreamReader(data).ReadToEndAsync();
        Console.WriteLine("Total length: " + stringData.Length);

        return MailProcessorResult.Okay;
    }
}