ช่วยดู code ส่งเมลให้ทีคับ รันผ่าน ส่งเรียบร้อยแต่ไม่เข้าเมลเลยคับ....

<? 
session_start(); 
mysql_connect("localhost","root","123456"); 
mysql_select_db("mydatabase"); 
if(trim($_POST["txtUsername"]) == "") 
{ 
echo "Please input Username!"; 
exit(); 
} 
if(trim($_POST["txtPassword"]) == "") 
{ 
echo "Please input Password!"; 
exit(); 
} 
if($_POST["txtPassword"] != $_POST["txtConPassword"]) 
{ 
echo "Password not Match!"; 
exit(); 
} 
if(trim($_POST["txtName"]) == "") 
{ 
echo "Please input Name!"; 
exit(); 
} 
if(trim($_POST["txtEmail"]) == "") 
{ 
echo "Please input Email!"; 
exit(); 
} 
$strSQL = "SELECT * FROM member WHERE Username = '".trim($_POST['txtUsername'])."' "; 
$objQuery = mysql_query($strSQL); 
$objResult = mysql_fetch_array($objQuery); 
if($objResult) 
{ 
echo "Username already exists!"; 
} 
else
{ 
$strSQL = "INSERT INTO member (Username,Password,Name,Email,Status,SID,Active) VALUES ('".$_POST["txtUsername"]."', 
'".$_POST["txtPassword"]."','".$_POST["txtName"]."' ,'".$_POST["txtEmail"]."','USER','".session_id()."','No')"; 
$objQuery = mysql_query($strSQL); 
$Uid = mysql_insert_id(); 

$strTo = $_POST["txtEmail"]; 
$strSubject = "Activate Member Account"; 
$strHeader = "Content-type: text/html; charset=windows-874\n"; // or UTF-8 // 
$strHeader .= "From: [email protected]\nReply-To: [email protected]"; 
$strMessage = ""; 
$strMessage .= "Welcome : ".$_POST["txtName"]."<br>"; 
$strMessage .= "=================================<br>"; 
$strMessage .= "Activate account click here.<br>"; 
$strMessage .= "https://www.thaicreate.com/activate.php?sid=".session_id()."&uid=".$Uid."<br>"; 
$strMessage .= "=================================<br>"; 
$strMessage .= "ThaiCreate.Com<br>"; 


    if (mail($strTo,$strSubject,$strMessage,$strHeader))
    {
       echo 'Register Completed!<br>Please check your email to activate account';
    } else {
       echo 'Can not send your email';
    }
} 
mysql_close(); 
?>