Dim loginEmail As String = "Spread@reasonables.com"

Dim loginPassword As String = "TEST0000-TEST-0000-TEST-0000TEST0000"

Dim fileStream As New System.IO.FileStream("D:\content1.xlsx", IO.FileMode.Open)

Dim arrayByte = New Byte(fileStream.Length - 1) {}

fileStream.Read(arrayByte, 0, fileStream.Length)

fileStream.Close()

Dim MySpread As New SpreadAPI.SpreadWebService()

Dim result As String = MySpread.UploadContactListFile(loginEmail, loginPassword, ".xlsx", arrayByte, "test 20130204")

/**
* @name     uploadContactListFile
* @function add multi email receivers
* @param
*  optInType  'Off'
*  (fiel import)
*		$data = the absolute path of file
* @return
*	errorMsg	failed information
*  Msg			success information
*/

public function uploadContactListFile($loginEmail,$password,$listName,$data ){
	    $fileContent = file_get_contents( $data );
            $fileName = array_pop( explode( '/', $data ) );
            $fileExt = array_pop( explode( '.', $fileName ) );
	    $addInArr = array(
			    'loginEmail'	    => $loginEmail,
			    'loginPassword'	    => $password,
			    'fileType'	            => '.'.$fileExt,
			    'myFileStream'	    => $fileContent,
			    'ContactListName'       => $listName
			    );
	    $Client = new SoapClient("http://service.rspread.com/Service.asmx?WSDL");		
	    $Client -> soap_defencoding = 'utf-8';
	    $Client -> decode_utf8 = false;
	    $Client -> xml_encoding = 'utf-8';
            return $Client -> UploadContactListFile( $addInArr );
}

POST {{YOUR_API_URL}}/service.asmx 

Content-Type: application/soap+xml; charset=utf-8
Content-Length: {{length}}

<?xml version="1.0" encoding="utf-8"?>
<soap12:Envelope xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:soap12="http://www.w3.org/2003/05/soap-envelope">
  <soap12:Body>
    <UploadContactListFile xmlns="http://service.reasonablespread.com/">
      <loginEmail>Spread@reasonables.com</loginEmail>
      <loginPassword>TEST0000-TEST-0000-TEST-0000TEST0000</loginPassword>
      <fileType>.csv</fileType>
      <myFileStream>base64Binary</myFileStream>
      <ContactListName>test 20130204</ContactListName>
    </UploadContactListFile>
  </soap12:Body>
</soap12:Envelope>