สอบถามการส่ง เมล์ด้วย SMTP มี 2 ตัวอย่าง แต่เลือกตัวอย่างที่ 2 แนะนำด้วยครับ ยังไม่เข้าใจ

<?PHP
$t_Email=$_REQUEST['txtEmail'];//เมล์ผู้ส่ง
$t_OrderNo=$_REQUEST['txtOrderNo'];//เรื่องที่ส่ง
$t_Desc=$_REQUEST['txtDesc'];//รายละเอียด


require("PHPMailer_v5/class.phpmailer.php");
$mail = new PHPMailer();

$body = $t_Desc;

$mail->CharSet = "utf-8";
$mail->IsSMTP();
$mail->SMTPDebug = 0;
$mail->SMTPAuth = true;
$mail->Host = "**********"; // SMTP server
$mail->Port = 25; // พอร์ท
$mail->Username = "*********"; // account SMTP
$mail->Password = "*******"; // รหัสผ่าน SMTP
$mail->SetFrom($t_Email, $t_Email);
$mail->AddReplyTo($t_Email, $t_Email);
//เรื่องที่ส่ง
$mail->Subject = $t_OrderNo;

$mail->MsgHTML($body);

$mail->AddAddress("[email protected]", "recipient"); // ผู้รับคนที่หนึ่ง



//******AddAttachment File : upload local file to server and attatch from server path-----------------------------------------------------------
if (isset($_FILES['fileField']) &&
  $_FILES['fileField']['error'] == UPLOAD_ERR_OK) {

  //check MIME TYPE อนุญาติเฉพาะนามสกุลที่กำหนด
  $finfo = new finfo(FILEINFO_MIME_TYPE);
  if (false === $ext = array_search(
    $finfo->file($_FILES['fileField']['tmp_name']),
    array(
        'jpg' => 'image/jpeg',
        'png' => 'image/png',
        'gif' => 'image/gif',
    ),
    true
  )) {
      throw new RuntimeException('Invalid file format.');
  }
  $destination = sprintf('uploads/%s.%s', sha1_file($_FILES['fileField']['tmp_name']), $ext);
  //move the file to a temp folder
  if (!move_uploaded_file($_FILES['fileField']['tmp_name'], $destination)) {
    throw new RuntimeException('Failed to move uploaded file.');
  }
  //Attach file
  $mail->AddAttachment($_FILES['fileField']['tmp_name'], basename($destination));
  //delete the file (ถ้าไม่ลบจะมีไฟล์อยู่ที่ server เพิ่มขึ้นเรื่อย)
 unlink($destination);
}

if(!$mail->Send())
{
echo "Mailer Error: " . $mail->ErrorInfo;
exit;
}
echo "Message has been sent";

?>

//Attach file
$mail->AddAttachment($_FILES['fileField']['tmp_name'], basename($destination));
unlink($destination);
}

<?php
require("PHPMailer_v5/class.phpmailer.php");
//get data nedeed !
$from = $_POST[from];
$to = $_POST[to];
$subject = $_POST[subject];
$message = $_POST[message];
//replace \n with <br>
$message = str_replace("\n", "<br>",$message);
//report
echo "<b><font color=#8080FF> From: $from </b><br>";
echo "<b>To: $to </b><br>";
echo "<b>Subject: $subject</b><br><br></font>";
// Obtain file upload variables
$fileatt = $_FILES['fileatt']['tmp_name'];
$fileatt_type = $_FILES['fileatt']['type'];
$fileatt_name = $_FILES['fileatt']['name'];

$headers = "From: $from \n";


// if($_FILES['fileatt']['size'] > 0)
if (is_uploaded_file($fileatt)) {
// Read the file to be attached ('rb' = read binary)
$file = fopen($fileatt,'rb');
$data = fread($file,filesize($fileatt));
fclose($file);
// Generate a boundary string
$semi_rand = md5(time());
$mime_boundary = "==Multipart_Boundary_x{$semi_rand}x";
// Add the headers for a file attachment
$headers .= "MIME-Version: 1.0\n" .
"Content-Type: multipart/mixed;\n" .
" boundary=\"{$mime_boundary}\"";
// Add a multipart boundary above the message
$message = "This is a multi-part message in MIME format.\n\n" .
"--{$mime_boundary}\n" .
"Content-Type: text/html; charset=\"UTF-8\"\n" .
"Content-Transfer-Encoding: 7bit\n\n" .
$message . "\n\n";

// Base64 encode the file data
$data = chunk_split(base64_encode($data));
// Add file attachment to the message
$message .= "--{$mime_boundary}\n" .
"Content-Type: {$fileatt_type};\n" .
" name=\"{$fileatt_name}\"\n" .
//"Content-Disposition: attachment;\n" .
//" filename=\"{$fileatt_name}\"\n" .
"Content-Transfer-Encoding: base64\n\n" .
$data . "\n\n" .
"--{$mime_boundary}--\n";
}else echo "File error! ";


$charset='UTF-8';
$encoded_subject="=?$charset?B?".base64_encode($subject)."?=\n";

//send the mail
if(mail($to, $encoded_subject, $message,$headers))echo "<b><font color=#FF0000>Message was send!<b></font>";
else echo "<b><font color=#FF0000>Message error!<b></font>";

?>