带有PDF附件标题的php邮件导致只进入邮件

I have a webform that generates a PDF which is emailed to me upon submission but the email keeps getting filtered to the spam for folder. I suspect that the something is wrong in the email header but not sure what it could be.

Any help is appreciated.

The following is a snippet...

// send by email
    $fileatt = '../pdfs/'.$filename;
    $fileatt_type = mime_content_type_manual($fileatt); // File Type  "application/pdf"
    $fileatt_name = $filename; // Filename that will be used for the file as the attachment 

    $email_from = "auth@mysite.com"; // Who the email is from 
    $email_subject = "Auth Report"; // The Subject of the email 

    //$email_to = "info@mysite.com";
    $email_to = "info@mysite.com";

    $headers = "From: ".$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"; 

    $headers .= "
MIME-Version: 1.0
" . 
    "Content-Type: multipart/mixed;
" . 
    " boundary=\"{$mime_boundary}\""; 

    $email_message .= "This is a multi-part message in MIME format.

" . 
    "--{$mime_boundary}
" . 
    "Content-Type:text/html; charset=\"iso-8859-1\"
" . 
    "Content-Transfer-Encoding: 7bit

" . 
    $email_message .= "

"; 

    $data = chunk_split(base64_encode($data)); 

    $email_message .= "--{$mime_boundary}
" . 
    "Content-Type: {$fileatt_type};
" . 
    " name=\"{$fileatt_name}\"
" . 
    "Content-Transfer-Encoding: base64

" . 
    $data .= "

" . 
    "--{$mime_boundary}--
";

If you add the sender of the email, which is auth@mysite.com for your case, as a new contact to the address book of your email client, then the email won't probably be marked as spam as it comes from a member of your contact address book.