Send Attachments with Amazon-SES

public Boolean SendRawEmail(String from, String to, String cc, String Subject, String text, String html, String replyTo, string attachPath)
    {
        AlternateView plainView = AlternateView.CreateAlternateViewFromString(text, Encoding.UTF8, "text/plain");
        AlternateView htmlView = AlternateView.CreateAlternateViewFromString(html, Encoding.UTF8, "text/html");

        MailMessage mailMessage = new MailMessage();

        mailMessage.From = new MailAddress(from);

        List<String> toAddresses = to.Replace(", ", ",").Split(',').ToList();

        foreach (String toAddress in toAddresses)
        {
            mailMessage.To.Add(new MailAddress(toAddress));
        }

        List<String> ccAddresses = cc.Replace(", ", ",").Split(',').Where(y => y != "").ToList();

        foreach (String ccAddress in ccAddresses)
        {
            mailMessage.CC.Add(new MailAddress(ccAddress));
        }

        mailMessage.Subject = Subject;
        mailMessage.SubjectEncoding = Encoding.UTF8;

        if (replyTo != null)
        {
            mailMessage.ReplyToList.Add(new MailAddress(replyTo));
        }

        if (text != null)
        {
            mailMessage.AlternateViews.Add(plainView);
        }

        if (html != null)
        {
            mailMessage.AlternateViews.Add(htmlView);
        }

        if (attachPath.Trim() != "")
        {
            if (System.IO.File.Exists(attachPath))
            {
                System.Net.Mail.Attachment objAttach = new System.Net.Mail.Attachment(attachPath);
                objAttach.ContentType = new ContentType("application/octet-stream"); 
                System.Net.Mime.ContentDisposition disposition = objAttach.ContentDisposition;
                disposition.DispositionType = "attachment";
                disposition.CreationDate = System.IO.File.GetCreationTime(attachPath);
                disposition.ModificationDate = System.IO.File.GetLastWriteTime(attachPath);
                disposition.ReadDate = System.IO.File.GetLastAccessTime(attachPath);
                mailMessage.Attachments.Add(objAttach);
            }
        }

        RawMessage rawMessage = new RawMessage();

        using (MemoryStream memoryStream = ConvertMailMessageToMemoryStream(mailMessage))
        {
            rawMessage.WithData(memoryStream);
        }

        SendRawEmailRequest request = new SendRawEmailRequest();
        request.WithRawMessage(rawMessage);

        request.WithDestinations(toAddresses);
        request.WithSource(from);

        AmazonSimpleEmailService ses = AWSClientFactory.CreateAmazonSimpleEmailServiceClient(ConfigurationManager.AppSettings.Get("AccessKeyId"), ConfigurationManager.AppSettings.Get("SecretKeyId"));

        try
        {
            SendRawEmailResponse response = ses.SendRawEmail(request);
            SendRawEmailResult result = response.SendRawEmailResult;
            return true;
        }
        catch (AmazonSimpleEmailServiceException ex)
        {
            return false;
        }
    }
    public static MemoryStream ConvertMailMessageToMemoryStream(MailMessage message)
    {
        Assembly assembly = typeof(SmtpClient).Assembly;
        Type mailWriterType = assembly.GetType("System.Net.Mail.MailWriter");
        MemoryStream fileStream = new MemoryStream();
        ConstructorInfo mailWriterContructor = mailWriterType.GetConstructor(BindingFlags.Instance | BindingFlags.NonPublic, null, new[] { typeof(Stream) }, null);
        object mailWriter = mailWriterContructor.Invoke(new object[] { fileStream });
        MethodInfo sendMethod = typeof(MailMessage).GetMethod("Send", BindingFlags.Instance | BindingFlags.NonPublic);
        sendMethod.Invoke(message, BindingFlags.Instance | BindingFlags.NonPublic, null, new[] { mailWriter, true }, null);
        MethodInfo closeMethod = mailWriter.GetType().GetMethod("Close", BindingFlags.Instance | BindingFlags.NonPublic);
        closeMethod.Invoke(mailWriter, BindingFlags.Instance | BindingFlags.NonPublic, null, new object[] { }, null);
        return fileStream;
    }

Found that here

Update: A method signature has changed in .NET 4.5, which breaks the above: Getting System.Net.Mail.MailMessage as a MemoryStream in .NET 4.5 beta