我有一个问题与发送邮件附件使用php

我有一个问题，发送邮件与附件使用php。邮件是用坏的附件发送的，例如当我试图发送大小为2 Mb的example.doc时，在邮件中我收到大小为1Kb的noname
我使用两个文件php.

第一个mailClass.php包含:

<?php 
class mail
{
function emailWithAttach($fromAdress,$toAdress,$mailSubject,$mailMessageHead,
                         $mailMessageMain,$mailMessageSign,$filePath,$fileName)
        {
            $fileatt_name = $fileName;
            $fileatt = $filePath.$fileName;
            $fileatt_type = "application/doc";
            $email_from = $fromaddress;
            $email_subject = $mailSubject;
            $email_message = $mailMessageHead. "<br>";
            $email_message .= $mailMessageMain. "<br>";
            $email_message .= $mailMessageSign;
            $email_to = $toAdress;
            $headers = "From: " .$email_from;
            $file = fopen ($fileatt."rb");
            $data = fread ($file, filesize($fileatt));
            fclose($file);
            $semi_rand = md5(time());
            $mime_boundary = "==Multipart_Boundary_x{$semi_rand}x";

            $headers .= "'nMIME-Version: 1.0 'n".
            "Content-Type : multipart/mixed:'n".
            "boundary='"{$mime_boundary}'"";
            $email_message .=  "This is a multip-part message in MIME format. 'n'n".
            "--{$mime_boundary}'n".
            "Content-Type : text/html; charset='"iso-8859-1'"'n".
            "Content-Transfer-Encoding: 7bit'n'n".
            $email_message .= "'n'n"; 
            $data = chunk_split(base64_encode($data));
            $email_message .= "--{$mime_boundary}'n".
            "Content-Type: {$fileatt_type}:'n".
            "name='"{$fileatt_name}'"'n".
            "Content-Transfer-Encoding: base64 'n'n".
            $data .= "'n'n".
            "--{$mime_boundary}--'n";
            if(@mail($email_to,$email_subject,$email_message,$headers))
            {
                return true;
            }  
        }
} 
?>

第二个文件index.php包含:

<?php
include "mailClass.php";
$testEmail = new mail;
$from = "sender@gmail.com";
$sendTo = "receiver@gmail.com";
$subject = "email with attachment";
$bodyHead = "welcome to the attachment email test";
$bodyMain = "hello iteb";
$bodyEnd = "Thank you";
$filePath = "";
$fileName = "example.doc";
if ($testEmail->emailWithAttach($from,$sendTo,$subject,$bodyHead,$bodyMain,$bodyEnd,$filePath,$fileName))
{
    echo "Email Send successful!!";
}   
else
{
    echo "Email Send Failed";
}
?>