php – 尽管base64在标头中发送,但附件无法识别

2023年12月13日 257次阅读

我在php邮件中发送附件时遇到问题.问题是电子邮件似乎已发送并已收到,但未被识别为附件.如果我进入邮件的来源,我可以看到它正在发送base64并包含附件名称,因此我很困惑,为什么它不会被客户端识别.有任何想法吗？

$uid = md5(uniqid(time()));
$headers = "From: ".$from_name." <".$mailto.">\n";
$headers .= "Reply-To: ".$from_mail."\n";
$headers .= "MIME-Version: 1.0\n";
$headers .= "Content-Type: multipart/mixed; boundary=\"".$uid."\"\n";
$headers .= "This is a multi-part message in MIME format.\n";
$headers .= "--".$uid."\n";
$headers .= "Content-type:text/plain\n";
$headers .= "Content-Transfer-Encoding: 8bit\n";
$headers .= $message."\n";

foreach ($_FILES as $file) {
    $name = $file['name'];
    $handle = fopen($file['tmp_name'], "r");
    $content = fread($handle, $file['size']);
    fclose($handle);
    $content = chunk_split(base64_encode($content));

    $headers .= "--{$uid}\n";
    $headers .= "Content-Type: {$file['type']}; name=\"{$name}\"\n";
    $headers .= "Content-Transfer-Encoding: base64\n";
    $headers .= "Content-Disposition: attachment; filename=\"{$name}\"\n";
    $headers .= $content;
}

$headers .= "--{$uid}--";
$mailto = 'myemail@email.com';
return mail($mailto, $subject, $message, $headers, '-f' . $mailto);

最佳答案 问题

您的代码有很多问题：

>电子邮件标题必须由CRLF终止.你只有LF.
> B64编码的文件和消息将添加到标头中.它们应该作为消息正文发送.
>每个部分的邮件头和邮件正文之间必须有一个额外的CRLF.
>身体部位必须用以CRLF开头的分隔符分隔.

电邮语法

根据RFC 2046,这是多部分消息体的结构的摘录.要特别注意CRLF. (BNF语法,有点简化.)


multipart-body := [preamble CRLF]
                  dash-boundary CRLF
                  body-part *encapsulation
                  close-delimiter
                  [CRLF epilogue]

dash-boundary := "--" boundary

body-part := MIME-part-headers [CRLF *OCTET]

encapsulation := delimiter
                 CRLF body-part

delimiter := CRLF dash-boundary

close-delimiter := delimiter "--"

代码

您的代码可能如下所示：

$uid = md5(uniqid(time()));
$headers = "From: ".$from_name." <".$mailto.">\r\n";
$headers .= "Reply-To: ".$from_mail."\r\n";
$headers .= "MIME-Version: 1.0\r\n";
$headers .= "Content-Type: multipart/mixed; boundary=\"".$uid."\"\r\n";

$body = "This is a multi-part message in MIME format.\n";
$body .= "--".$uid."\r\n";
$body .= "Content-type:text/plain\r\n";
$body .= "Content-Transfer-Encoding: 8bit\r\n";
$body .= "\r\n";
$body .= $message;

foreach ($_FILES as $file) {
  $name = $file['name'];
  $handle = fopen($file['tmp_name'], "r");
  $content = fread($handle, $file['size']);
  fclose($handle);
  $content = chunk_split(base64_encode($content));

  $body .= "\r\n--{$uid}\r\n";
  $body .= "Content-Type: {$file['type']}; name=\"{$name}\"\r\n";
  $body .= "Content-Transfer-Encoding: base64\r\n";
  $body .= "Content-Disposition: attachment; filename=\"{$name}\"\r\n";
  $body .= "\r\n";
  $body .= $content;
}

$body .= "\r\n--{$uid}--";
$mailto = 'myemail@email.example';
return mail($mailto, $subject, $body, $headers, '-f' . $mailto);

参考

> RFC 5322 Internet Message Format
> RFC 2045 (MIME) Part One: Format of Internet Message Bodies
> RFC 2046 (MIME) Part Two: Media Types

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