如何通过 PHP 表单发送带有附件的电子邮件？
【问题讨论】：
标签： php email attachment
正如其他人在回答中所建议的那样，最好使用现有工具。但是，如果您想自己动手或只是了解如何操作，请继续阅读。
在您的 HTML 中发送文件附件实际上只有两个要求。
enctype="multipart/form-data"
<input type="file" name="examplefile">。这允许用户浏览要附加的文件。如果您同时具备这两个条件，浏览器会将所有附件连同表单提交一起上传。
旁注：这些文件在服务器上保存为临时文件。在本例中，我们将获取他们的数据并通过电子邮件发送，但如果您将临时文件移动到永久位置，则您只是创建了一个文件上传表单。
This tutorial 非常适合理解如何在 PHP 中构建 MIME 电子邮件（可以包含 HTML 内容、纯文本版本、附件等）。我以它为起点。
基本上，你会做三件事：
content-type，例如image/jpg 或application/pdf. 更多信息可以在here 找到。 （我的示例脚本使用内置 PHP 函数从每个文件中提取这些信息。）提交表单后，浏览器上传的任何文件（参见 HTML 部分）都将通过 $_FILES 变量提供，该变量包含“通过 HTTP POST 方法上传到当前脚本的项目的关联数组。 '
$_FILES 上的documentation 很糟糕，但是在上传之后，您可以运行print_r($_FILES) 来查看它是如何工作的。它会输出如下内容：
Array ( [examplefile] => Array ( [name] => your_filename.txt
[type] => text/plain [tmp_name] =>
C:\path\to\tmp\file\something.tmp [error] => 0 [size] => 200 ) )
然后您可以使用file_get_contents($_FILES['examplefile']['tmp_name']) 获取相关临时文件中的数据。
php.ini 有一些限制附件大小的设置。请参阅this discussion 了解更多信息。
我创建了以下函数，该函数可以包含在页面中并用于收集通过表单提交的任何文件附件。随意使用它和/或根据您的需要调整它。
总附件限制是任意的，但大量可能会使mail() 脚本陷入困境或被发送或接收电子邮件服务器拒绝。进行自己的测试。
（注意：PHP 中的mail() 函数依赖于php.ini 中的信息来知道如何发送您的电子邮件。）
function sendWithAttachments($to, $subject, $htmlMessage){
$maxTotalAttachments=2097152; //Maximum of 2 MB total attachments, in bytes
$boundary_text = "anyRandomStringOfCharactersThatIsUnlikelyToAppearInEmail";
$boundary = "--".$boundary_text."\r\n";
$boundary_last = "--".$boundary_text."--\r\n";
//Build up the list of attachments,
//getting a total size and adding boundaries as needed
$emailAttachments = "";
$totalAttachmentSize = 0;
foreach ($_FILES as $file) {
//In case some file inputs are left blank - ignore them
if ($file['error'] == 0 && $file['size'] > 0){
$fileContents = file_get_contents($file['tmp_name']);
$totalAttachmentSize += $file['size']; //size in bytes
$emailAttachments .= "Content-Type: "
.$file['type'] . "; name=\"" . basename($file['name']) . "\"\r\n"
."Content-Transfer-Encoding: base64\r\n"
."Content-disposition: attachment; filename=\""
.basename($file['name']) . "\"\r\n"
."\r\n"
//Convert the file's binary info into ASCII characters
.chunk_split(base64_encode($fileContents))
.$boundary;
}
}
//Now all the attachment data is ready to insert into the email body.
//If the file was too big for PHP, it may show as having 0 size
if ($totalAttachmentSize == 0) {
echo "Message not sent. Either no file was attached, or it was bigger than PHP is configured to accept.";
}
//Now make sure it doesn't exceed this function's specified limit:
else if ($totalAttachmentSize>$maxTotalAttachments) {
echo "Message not sent. Total attachments can't exceed " . $maxTotalAttachments . " bytes.";
}
//Everything is OK - let's build up the email
else {
$headers = "From: yourserver@example.com\r\n";
$headers .= "MIME-Version: 1.0\r\n"
."Content-Type: multipart/mixed; boundary=\"$boundary_text\"" . "\r\n";
$body .="If you can see this, your email client "
."doesn't accept MIME types!\r\n"
.$boundary;
//Insert the attachment information we built up above.
//Each of those attachments ends in a regular boundary string
$body .= $emailAttachments;
$body .= "Content-Type: text/html; charset=\"iso-8859-1\"\r\n"
."Content-Transfer-Encoding: 7bit\r\n\r\n"
//Inert the HTML message body you passed into this function
.$htmlMessage . "\r\n"
//This section ends in a terminating boundary string - meaning
//"that was the last section, we're done"
.$boundary_last;
if(mail($to, $subject, $body, $headers))
{
echo "<h2>Thanks!</h2>Form submitted to " . $to . "<br />";
} else {
echo 'Error - mail not sent.';
}
}
}
如果您想查看这里发生了什么，请注释掉对mail() 的调用，并让它将输出回显到您的屏幕上。
【讨论】：
为了发送实际的电子邮件，我建议使用PHPMailer library，它让一切变得更容易。
【讨论】：
代码
<?php
//define the receiver of the email
$to = 'youraddress@example.com';
//define the subject of the email
$subject = 'Test email with attachment';
//create a boundary string. It must be unique
//so we use the MD5 algorithm to generate a random hash
$random_hash = md5(date('r', time()));
//define the headers we want passed. Note that they are separated with \r\n
$headers = "From: webmaster@example.com\r\nReply-To: webmaster@example.com";
//add boundary string and mime type specification
$headers .= "\r\nContent-Type: multipart/mixed; boundary=\"PHP-mixed-".$random_hash."\"";
//read the atachment file contents into a string,
//encode it with MIME base64,
//and split it into smaller chunks
$attachment = chunk_split(base64_encode(file_get_contents('attachment.zip')));
//define the body of the message.
ob_start(); //Turn on output buffering
?>
--PHP-mixed-<?php echo $random_hash; ?>
Content-Type: multipart/alternative; boundary="PHP-alt-<?php echo $random_hash; ?>"
--PHP-alt-<?php echo $random_hash; ?>
Content-Type: text/plain; charset="iso-8859-1"
Content-Transfer-Encoding: 7bit
Hello World!!!
This is simple text email message.
--PHP-alt-<?php echo $random_hash; ?>
Content-Type: text/html; charset="iso-8859-1"
Content-Transfer-Encoding: 7bit
<h2>Hello World!</h2>
<p>This is something with <b>HTML</b> formatting.</p>
--PHP-alt-<?php echo $random_hash; ?>--
--PHP-mixed-<?php echo $random_hash; ?>
Content-Type: application/zip; name="attachment.zip"
Content-Transfer-Encoding: base64
Content-Disposition: attachment
<?php echo $attachment; ?>
--PHP-mixed-<?php echo $random_hash; ?>--
<?php
//copy current buffer contents into $message variable and delete current output buffer
$message = ob_get_clean();
//send the email
$mail_sent = @mail( $to, $subject, $message, $headers );
//if the message is sent successfully print "Mail sent". Otherwise print "Mail failed"
echo $mail_sent ? "Mail sent" : "Mail failed";
?>
【讨论】：
您可能想查看SwiftMailer。它有一个不错的tutorial on this。
【讨论】：