PHP 警告：mail()：SMTP 服务器响应：501 必须指定地址

Question

无法理解为什么我会收到此错误 - 发件人和收件人的电子邮件地址都是有效的（我每天都使用它们）所以无法弄清楚这是怎么发生的 - 任何帮助都将不胜感激。

注意：这在生产环境中有效，但在开发环境中会出错。我在开发环境中有更严格的配置。注意：我正在使用 smtp4dev 在 PC 上进行本地测试

$to = 'recipient <[email protected]>';
$cc = 'copy <[email protected]>';
$from = 'sender <[email protected]>';
$filename = 'Invoice#'.$order_id.'.pdf';
$message = file_get_contents(ROOT_DIR.'admin/include/email-body.html');
$content = chunk_split(base64_encode($pdf_file));
$uid = md5(uniqid(time()));

$headers  = 'MIME-Version: 1.0' . "\r\n";
$headers .= 'To: '. $to . "\r\n";
$headers .= 'Cc: '. $cc . "\r\n";
$headers .= 'From: '. $from . "\r\n";
$headers .= "Content-Type: multipart/mixed; boundary=\"".$uid."\"\r\n\r\n";
$headers .= "This is a multi-part message in MIME format.\r\n";
$headers .= "--".$uid."\r\n";
$headers .= "Content-type:text/html; charset=iso-8859-1\r\n";
$headers .= "Content-Transfer-Encoding: 7bit\r\n\r\n";
$headers .= $message."\r\n\r\n";
$headers .= "--".$uid."\r\n";
$headers .= "Content-Type: application/pdf; name=\"".$filename."\"\r\n";
$headers .= "Content-Transfer-Encoding: base64\r\n";
$headers .= "Content-Disposition: attachment; filename=\"".$filename."\"\r\n\r\n";
$headers .= $content."\r\n\r\n";
$headers .= "--".$uid."--";

if (mail($to, $subject, $message, $headers)) {
  print "SUCCESS";
} else {
  print "FALIED";
}

如果我在 mail() 行上打印变量，结果如下：

mail(recipient <[email protected]>, Company - Invoice#12451, "",
MIME-Version: 1.0 
To: recipient <[email protected]> 
Cc: copy <[email protected]> 
From: sender <[email protected]> 
Content-Type: multipart/mixed;
boundary="2c88ff549e67c83e7a6e3df0bffe9dc9"

This is a multi-part message in MIME format.
--2c88ff549e67c83e7a6e3df0bffe9dc9 Content-type:text/html;
charset=iso-8859-1 Content-Transfer-Encoding: 7bit

---> html message body stripped <---


--2c88ff549e67c83e7a6e3df0bffe9dc9 Content-Type: application/pdf;
name="Invoice#12451.pdf" Content-Transfer-Encoding: base64
Content-Disposition: attachment; filename="Invoice#12451.pdf"

--> pdf attachment stripped <--


--2c88ff549e67c83e7a6e3df0bffe9dc9--)

Answer 1

您的 $to 必须只是邮件地址。SMTP 对话框需要尖括号中的邮件地址，并且您要向其提供 To: 标头的内容。$from 也一样。