在与格式糟糕的附件斗争了一段时间后，我使用了以下代码:

$email = new PHPMailer();
$email->From      = 'from@somedomain.com';
$email->FromName  = 'FromName';
$email->Subject   = 'Subject';
$email->Body      = 'Body';
$email->AddAddress( 'to@somedomain.com' );
$email->AddAttachment( "/path/to/filename.ext" , "filename.ext", 'base64', 'application/octet-stream' );
$email->Send();

要发送带有附件的电子邮件，我们需要使用multipart/mixed MIME类型，该类型指定混合类型将包含在电子邮件中。此外，我们希望使用多部分/替代MIME类型来发送纯文本和HTML版本的电子邮件。看一下这个例子:

<?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"; 
?>

正如你所看到的，发送带有附件的电子邮件很容易完成。在前面的例子中，我们有多部分/混合MIME类型，在里面我们有多部分/替代MIME类型，指定两个版本的电子邮件。为了将附件包含到消息中，我们将指定文件中的数据读入一个字符串，使用base64对其进行编码，将其分割为更小的块，以确保它与MIME规范匹配，然后将其作为附件包含。

从这里拍的。

工作理念:

if (isset($_POST['submit'])) {
    $mailto = $_POST["mailTo"];
    $from_mail = $_POST["fromEmail"];
    $replyto = $_POST["fromEmail"];
    $from_name = $_POST["fromName"];
    $message = $_POST["message"];
    $subject = $_POST["subject"];

    $filename = $_FILES["fileAttach"]["name"];
    $content = chunk_split(base64_encode(file_get_contents($_FILES["fileAttach"]["tmp_name"])));

    $uid = md5(uniqid(time()));
    $name = basename($file);
    $header = "From: " . $from_name . " <" . $from_mail . ">\r\n";
    $header .= "Reply-To: " . $replyto . "\r\n";

    $header .= "MIME-Version: 1.0\r\n";
    $header .= "Content-Type: multipart/mixed; boundary=\"" . $uid . "\"\r\n\r\n";
    $header .= "This is a multi-part message in MIME format.\r\n";
    $header .= "--" . $uid . "\r\n";

// You add html "Content-type: text/html; charset=utf-8\n" or for Text "Content-type:text/plain; charset=iso-8859-1\r\n" by I.khan
    $header .= "Content-type:text/html; charset=utf-8\n";
    $header .= "Content-Transfer-Encoding: 7bit\r\n\r\n";

// User Message you can add HTML if You Selected HTML content
    $header .= "<div style='color: red'>" . $message . "</div>\r\n\r\n";

    $header .= "--" . $uid . "\r\n";
    $header .= "Content-Type: application/octet-stream; name=\"" . $filename . "\"\r\n"; // use different content types here
    $header .= "Content-Transfer-Encoding: base64\r\n";
    $header .= "Content-Disposition: attachment; filename=\"" . $filename . "\"\r\n\r\n"; // For Attachment
    $header .= $content . "\r\n\r\n";
    $header .= "--" . $uid . "--";
    if (mail($mailto, $subject, "", $header)) {
        echo "<script>alert('Success');</script>"; // or use booleans here
    } else {
        echo "<script>alert('Failed');</script>";
    }
}

这对我很有用。它还附加了多个附件。很容易

<?php

if ($_POST && isset($_FILES['file'])) {
    $recipient_email = "recipient@yourmail.com"; //recepient
    $from_email = "info@your_domain.com"; //from email using site domain.
    $subject = "Attachment email from your website!"; //email subject line

    $sender_name = filter_var($_POST["s_name"], FILTER_SANITIZE_STRING); //capture sender name
    $sender_email = filter_var($_POST["s_email"], FILTER_SANITIZE_STRING); //capture sender email
    $sender_message = filter_var($_POST["s_message"], FILTER_SANITIZE_STRING); //capture message
    $attachments = $_FILES['file'];

    //php validation
    if (strlen($sender_name) < 4) {
        die('Name is too short or empty');
    }
    if (!filter_var($sender_email, FILTER_VALIDATE_EMAIL)) {
        die('Invalid email');
    }
    if (strlen($sender_message) < 4) {
        die('Too short message! Please enter something');
    }

    $file_count = count($attachments['name']); //count total files attached
    $boundary = md5("specialToken$4332"); // boundary token to be used

    if ($file_count > 0) { //if attachment exists
        //header
        $headers = "MIME-Version: 1.0\r\n";
        $headers .= "From:" . $from_email . "\r\n";
        $headers .= "Reply-To: " . $sender_email . "" . "\r\n";
        $headers .= "Content-Type: multipart/mixed; boundary = $boundary\r\n\r\n";

        //message text
        $body = "--$boundary\r\n";
        $body .= "Content-Type: text/plain; charset=ISO-8859-1\r\n";
        $body .= "Content-Transfer-Encoding: base64\r\n\r\n";
        $body .= chunk_split(base64_encode($sender_message));

        //attachments
        for ($x = 0; $x < $file_count; $x++) {
            if (!empty($attachments['name'][$x])) {

                if ($attachments['error'][$x] > 0) { //exit script and output error if we encounter any
                    $mymsg = array(
                        1 => "The uploaded file exceeds the upload_max_filesize directive in php.ini",
                        2 => "The uploaded file exceeds the MAX_FILE_SIZE directive that was specified in the HTML form",
                        3 => "The uploaded file was only partially uploaded",
                        4 => "No file was uploaded",
                        6 => "Missing a temporary folder");
                    die($mymsg[$attachments['error'][$x]]);
                }

                //get file info
                $file_name = $attachments['name'][$x];
                $file_size = $attachments['size'][$x];
                $file_type = $attachments['type'][$x];

                //read file 
                $handle = fopen($attachments['tmp_name'][$x], "r");
                $content = fread($handle, $file_size);
                fclose($handle);
                $encoded_content = chunk_split(base64_encode($content)); //split into smaller chunks (RFC 2045)

                $body .= "--$boundary\r\n";
                $body .= "Content-Type: $file_type; name=" . $file_name . "\r\n";
                $body .= "Content-Disposition: attachment; filename=" . $file_name . "\r\n";
                $body .= "Content-Transfer-Encoding: base64\r\n";
                $body .= "X-Attachment-Id: " . rand(1000, 99999) . "\r\n\r\n";
                $body .= $encoded_content;
            }
        }
    } else { //send plain email otherwise
        $headers = "From:" . $from_email . "\r\n" .
                "Reply-To: " . $sender_email . "\n" .
                "X-Mailer: PHP/" . phpversion();
        $body = $sender_message;
    }

    $sentMail = @mail($recipient_email, $subject, $body, $headers);
    if ($sentMail) { //output success or failure messages
        die('Thank you for your email');
    } else {
        die('Could not send mail! Please check your PHP mail configuration.');
    }
}
?>

由于它们指定的附件格式(application/octet-stream)，上面的答案都不适合我。使用application/pdf可获得pdf文件的最佳效果。

<?php

// just edit these 
$to          = "email1@domain.com, email2@domain.com"; // addresses to email pdf to
$from        = "sent_from@domain.com"; // address message is sent from
$subject     = "Your PDF email subject"; // email subject
$body        = "<p>The PDF is attached.</p>"; // email body
$pdfLocation = "./your-pdf.pdf"; // file location
$pdfName     = "pdf-file.pdf"; // pdf file name recipient will get
$filetype    = "application/pdf"; // type

// creates headers and mime boundary
$eol = PHP_EOL;
$semi_rand     = md5(time());
$mime_boundary = "==Multipart_Boundary_$semi_rand";
$headers       = "From: $from$eolMIME-Version: 1.0$eol" .
    "Content-Type: multipart/mixed;$eol boundary=\"$mime_boundary\"";

// add html message body
$message = "--$mime_boundary$eol" .
    "Content-Type: text/html; charset=\"iso-8859-1\"$eol" .
    "Content-Transfer-Encoding: 7bit$eol$eol$body$eol";

// fetches pdf
$file = fopen($pdfLocation, 'rb');
$data = fread($file, filesize($pdfLocation));
fclose($file);
$pdf = chunk_split(base64_encode($data));

// attaches pdf to email
$message .= "--$mime_boundary$eol" .
    "Content-Type: $filetype;$eol name=\"$pdfName\"$eol" .
    "Content-Disposition: attachment;$eol filename=\"$pdfName\"$eol" .
    "Content-Transfer-Encoding: base64$eol$eol$pdf$eol--$mime_boundary--";

// Sends the email
if(mail($to, $subject, $message, $headers)) {
    echo "The email was sent.";
}
else {
    echo "There was an error sending the mail.";
}

针对PHP 5.5.27的安全更新

$file = $path.$filename;
$content = file_get_contents( $file);
$content = chunk_split(base64_encode($content));
$uid = md5(uniqid(time()));
$file_name = basename($file);

// header
$header = "From: ".$from_name." <".$from_mail.">\r\n";
$header .= "Reply-To: ".$replyto."\r\n";
$header .= "MIME-Version: 1.0\r\n";
$header .= "Content-Type: multipart/mixed; boundary=\"".$uid."\"\r\n\r\n";

// message & attachment
$nmessage = "--".$uid."\r\n";
$nmessage .= "Content-type:text/plain; charset=iso-8859-1\r\n";
$nmessage .= "Content-Transfer-Encoding: 7bit\r\n\r\n";
$nmessage .= $message."\r\n\r\n";
$nmessage .= "--".$uid."\r\n";
$nmessage .= "Content-Type: application/octet-stream; name=\"".$filename."\"\r\n";
$nmessage .= "Content-Transfer-Encoding: base64\r\n";
$nmessage .= "Content-Disposition: attachment; filename=\"".$file_name."\"\r\n\r\n";
$nmessage .= $content."\r\n\r\n";
$nmessage .= "--".$uid."--";

if (mail($mailto, $subject, $nmessage, $header)) {
    return true; // Or do something here
} else {
  return false;
}