使用 PHP 邮件程序发送带有附件的邮件时出错：交易失败：缺少起始边界 SMTP 代码：554

Question

我正在尝试发送带有 pdf 附件的 php 邮件程序电子邮件，并显示此错误：电子邮件未发送。错误：SMTP 错误：数据不被接受。SMTP 服务器错误：DATA END 命令失败详细信息：事务失败：缺少起始边界 SMTP 代码：554我试图在所有地方添加 mime 边界，但结果相同。<?phpinclude dirname(__FILE__) . '/../views/pdf-receipt.php';function sendMailTest(    $recipient_mail, $recipient_name, $from_mail, $from_name, $subject, $body, $body_without_html, $attachments=NULL) {    require 'folder/PHPMailer-5.2.26/PHPMailerAutoload.php';    $mail = new PHPMailer;    try {        $mail->isSMTP();        $mail->setFrom($from_mail, $from_name);        $mail->addAddress($recipient_mail, $recipient_name);        $mime_boundary = "Name of company".md5(time());        $mail->SMTPDebug = true;        $mail->Host = 'email-smtp.eu-west-1.amazonaws.com';        $mail->Username = 'XXX';        $mail->Password = 'XXX';        $mail->Encoding = 'quoted-printable';        $mail->addCustomHeader('Content-ID', '20cca', 'Content-Type', 'multipart/mixed', 'boundary='.$mime_boundary.'\n');        $mail->Body = "--$mime_boundary\n";        $mail->CharSet = 'UTF-8';        $mail->Subject = utf8_encode($subject);        $mail->Body .= "Hey\n";        $mail->AltBody .= "--$mime_boundary\n".$body_without_html;        $mail->SMTPAuth = true;        $mail->SMTPSecure = 'tls';        $mail->Port = 000;        $mail->isHTML(true);        $data = '%PDF-1.2 6 0 obj << /S /GoTo /D (chapter.1) >>';               // if i comment line below email is sent properly,         // if i use AddAttachment local pdf file its working also,         // but i use TCPD generated PDF and attaching it, if i will         // just write it out to the message body i will see it as a         // text or if i will attach 'addStringEmbeddedImage' its         //displayed correctly but on same line as message text  我希望通过附件发送电子邮件，但看不到起始边界错误。