เกิด error Notice: Array to string conversion in /home/crm/public_html/project/test/blastmail/test23.php on line 17 ทำไงหรอคะ

<?php
$con = mysql_connect("localhost","root","aaa");
if (!$con)
  {
  die('ติดต่อฐานข้อมูลไม่ได้: ' . mysql_error());
  }

mysql_select_db("bb", $con);

$result = mysql_query("SELECT email_address FROM leads");

while($row = mysql_fetch_array($result))
  {
  //echo $row['Emailaddress'];
  //echo "<br />";

  $email_address_caps = strtoupper($row);

 mysql_query("INSERT INTO Email_addresses(email_address,email_address_caps) 
VALUES('$row','$email_address_caps')");
  }
////////////////////////////////////////////////////////////////////

$query = mysql_query("SELECT id FROM leads");

while($row2 = mysql_fetch_array($query))
{
 mysql_query("INSERT INTO email_addr_bean_rel(bean_id,bean_module,primary_add,reply_to_address) 
 VALUES('$row2','Leads','1','0')");
}
///////////////////////////////////////////////////


$query4 = mysql_query("select id FROM email_addresses");

while($id_mail = mysql_fetch_array($query4))
{
$mailaddress =  mysql_query("SELECT email_address FROM email_addresses WHERE id='$id_mail'");

$id_lead = mysql_query("SELECT id FROM leads WHERE email_address = '$mailaddress'");

mysql_query("INSERT INTO email_addr_bean_rel(email_address_id) VALUES ('$id_mail') WHERE bean_id = '$id_lead' ");

}

?>