java.io.ioexception server not responding ok to MAIL FROM;501 5.1.7 Bad Server error syntax

Hi Experts,

Kindly help me with this error in receiver mail adapter. I  tried using Java mapping to send a file as attachment in mail .

Jre version :6

Jse Version :1.6

PI : 7.40

Code where my E-mail Id is specified :

public void execute(InputStream in, OutputStream out) throws StreamTransformationException {

     String mailSubject = "hi";

     String mailSender = "\"<abc@xyz.com>";

     String mailReceiver = "\"<abc@xyz.com>";

     String attachmentName = "mail.txt";

     String replyto="";

     String boundary = "--AaZz";

     String mailContent = "test mail";

     String CRLF = "\r\n";

     try {

       // create XML structure of mail package

       String output =

             "<?xml version=\"1.0\" encoding=\"UTF-8\"?>"

         + "<ns:Mail xmlns:ns=\"http://sap.com/xi/XI/Mail/30\">"

         + "<Subject>" + mailSubject + "</Subject>"

         + "<From>" + mailSender + "</From>"

         + "<To>" + mailReceiver + "</To>"

         + "<Reply_To>" + replyto + "</Reply_To>"

         + "<Content_Type>multipart/mixed; boundary=\""

         + boundary

         + "\"</Content_Type>"

         + "<Content>";

         out.write(output.getBytes());

       // create the declaration of the MIME parts

       //First part

       output = "--" + boundary + CRLF

                 + "Content-Type: text/plain; charset=UTF-8" + CRLF

                 + "Content-Disposition: inline" + CRLF + CRLF

                 + mailContent + CRLF + CRLF

       //Second part

                 + "--" + boundary + CRLF

                 + "Content-Type: application/xml; name=" + attachmentName + CRLF

                 + "Content-Disposition: attachment; filename=" + attachmentName + CRLF + CRLF;

       out.write(output.getBytes());

       //Source is taken as attachment

       copySource(in, out);

       // last boundary

       output = CRLF + CRLF +"--" + boundary + "--" + CRLF;

       out.write(output.getBytes());

       // finish mail package

       out.write("</Content></ns:Mail>".getBytes());

     } catch (IOException e) {

       throw new StreamTransformationException(e.getMessage());

     }

   }

   protected static void copySource(InputStream in, OutputStream out) throws IOException {

     byte[] buf = new byte[in.available()];

     in.read(buf);

     String sbuf = new String(buf);

     // replace all control characters with escape sequences

     sbuf = sbuf.replaceAll("&", "&amp;");

     sbuf = sbuf.replaceAll("\"", "&quot;");

     sbuf = sbuf.replaceAll("'", "&apos;");

     sbuf = sbuf.replaceAll("<", "&lt;");

     sbuf = sbuf.replaceAll(">", "&gt;");

     out.write(sbuf.getBytes("UTF-8"));

   }

Please help