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。

你可以使用我创建的这个类发送常规邮件或附件邮件。

下面是如何使用它的示例链接。

https://github.com/Nerdtrix/EZMAIL

从此页复制代码-在mail()中工作

他首先创建了一个可以稍后调用的mail_attachment函数。他稍后用他的附件代码来做。

<?php
function mail_attachment($filename, $path, $mailto, $from_mail, $from_name, $replyto, $subject, $message) {
    $file = $path.$filename;
    $file_size = filesize($file);
    $handle = fopen($file, "r");
    $content = fread($handle, $file_size);
    fclose($handle);
    $content = chunk_split(base64_encode($content));
    $uid = md5(uniqid(time()));
    $header = "From: ".$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";
    $header .= "Content-type:text/plain; charset=iso-8859-1\r\n";
    $header .= "Content-Transfer-Encoding: 7bit\r\n\r\n";
    $header .= $message."\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";
    $header .= $content."\r\n\r\n";
    $header .= "--".$uid."--";
    if (mail($mailto, $subject, "", $header)) {
        echo "mail send ... OK"; // or use booleans here
    } else {
        echo "mail send ... ERROR!";
    }
}

//start editing and inputting attachment details here
$my_file = "somefile.zip";
$my_path = "/your_path/to_the_attachment/";
$my_name = "Olaf Lederer";
$my_mail = "my@mail.com";
$my_replyto = "my_reply_to@mail.net";
$my_subject = "This is a mail with attachment.";
$my_message = "Hallo,\r\ndo you like this script? I hope it will help.\r\n\r\ngr. Olaf";
mail_attachment($my_file, $my_path, "recipient@mail.org", $my_mail, $my_name, $my_replyto, $my_subject, $my_message);
?>

他在他的页面上有更多的细节，并在评论区回答了一些问题。

Swiftmailer是另一个易于使用的脚本，可以自动防止电子邮件注入，使附件变得轻而易举。我也强烈反对使用PHP内置的mail()函数。

使用方法:

下载Swiftmailer，并将lib文件夹放在你的项目中 使用require_once 'lib/swift_required.php'包含主文件;

现在当你需要邮寄时添加代码:

// Create the message
$message = Swift_Message::newInstance()
    ->setSubject('Your subject')
    ->setFrom(array('webmaster@mysite.com' => 'Web Master'))
    ->setTo(array('receiver@example.com'))
    ->setBody('Here is the message itself')
    ->attach(Swift_Attachment::fromPath('myPDF.pdf'));

//send the message          
$mailer->send($message);

更多信息和选项可以在Swiftmailer文档中找到。

我最终编写了自己的电子邮件发送/编码函数。这在我发送PDF附件时效果很好。我还没有在生产中使用其他特性。

注意:尽管规范非常强调必须使用\r\n来分隔头文件，但我发现它只在使用PHP_EOL时有效。我只在Linux上测试过这个功能。YMMV

<?php
# $args must be an associative array
#     required keys: from, to, body
#          body can be a string or a [tree of] associative arrays. See examples below
#     optional keys: subject, reply_to, cc, bcc
# EXAMPLES:
#    # text-only email:
#    email2(array(
#        'from' => 'noreply@foo.com',
#        'to' => 'jason@jasonwoof.com',
#        'subject' => 'test',
#        # body will be text/plain because we're passing a string that doesn't start with '<'
#        'body' => 'Hi, testing 1 2 3',
#    ));
#
#    # html-only email
#    email2(array(
#        'from' => 'noreply@foo.com',
#        'to' => 'jason@jasonwoof.com',
#        'subject' => 'test',
#        # body will be text/html because we're passing a string that starts with '<'
#        'body' => '<h1>Hi!</h1>I like <a href="http://cheese.com">cheese</a>',
#    ));
#
#    # text-only email (explicitly, in case first character is dynamic or something)
#    email2(array(
#        'from' => 'noreply@foo.com',
#        'to' => 'jason@jasonwoof.com',
#        'subject' => 'test',
#        # body will be text/plain because we're passing a string that doesn't start with '<'
#        'body' => array(
#            'type' => 'text',
#            'body' => $message_text,
#        )
#    ));
#
#    # email with text and html alternatives (auto-detected mime types)
#    email2(array(
#        'from' => 'noreply@foo.com',
#        'to' => 'jason@jasonwoof.com',
#        'subject' => 'test',
#        'body' => array(
#            'type' => 'alternatives',
#            'body' => array(
#                "Hi!\n\nI like cheese",
#                '<h1>Hi!</h1><p>I like <a href="http://cheese.com">cheese</a></p>',
#            )
#        )
#    ));
#
#    # email with text and html alternatives (explicit types)
#    email2(array(
#        'from' => 'noreply@foo.com',
#        'to' => 'jason@jasonwoof.com',
#        'subject' => 'test',
#        'body' => array(
#            'type' => 'alternatives',
#            'body' => array(
#                array(
#                    'type' => 'text',
#                    'body' => "Hi!\n\nI like cheese",
#                ),
#                array(
#                    'type' => 'html',
#                    'body' => '<h1>Hi!</h1><p>I like cheese</p>',
#                ),
#            )
#        )
#    ));
#
#    # email with an attachment
#    email2(array(
#        'from' => 'noreply@foo.com',
#        'to' => 'jason@jasonwoof.com',
#        'subject' => 'test',
#        'body' => array(
#            'type' => 'mixed',
#            'body' => array(
#                "Hi!\n\nCheck out this (inline) image",
#                array(
#                    'type' => 'image/png',
#                    'disposition' => 'inline',
#                    'body' => $image_data, # raw file contents
#                ),
#                "Hi!\n\nAnd here's an attachment",
#                array(
#                    'type' => 'application/pdf; name="attachment.pdf"',
#                    'disposition' => 'attachment; filename="attachment.pdf"',
#                    'body' => $pdf_data, # raw file contents
#                ),
#                "Or you can use shorthand:",
#                array(
#                    'type' => 'application/pdf',
#                    'attachment' => 'attachment.pdf', # name for client (not data source)
#                    'body' => $pdf_data, # raw file contents
#                ),
#            )
#        )
#    ))
function email2($args) {
    if (!isset($args['from'])) { return 1; }
    $from = $args['from'];
    if (!isset($args['to'])) { return 2; }
    $to = $args['to'];
    $subject = isset($args['subject']) ? $args['subject'] : '';
    $reply_to = isset($args['reply_to']) ? $args['reply_to'] : '';
    $cc = isset($args['cc']) ? $args['cc'] : '';
    $bcc = isset($args['bcc']) ? $args['bcc'] : '';

    #FIXME should allow many more characters here (and do Q encoding)
    $subject = isset($args['subject']) ? $args['subject'] : '';
    $subject = preg_replace("|[^a-z0-9 _/#'.:&,-]|i", '_', $subject);

    $headers = "From: $from";
    if($reply_to) {
        $headers .= PHP_EOL . "Reply-To: $reply_to";
    }
    if($cc) {
        $headers .= PHP_EOL . "CC: $cc";
    }
    if($bcc) {
        $headers .= PHP_EOL . "BCC: $bcc";
    }

    $r = email2_helper($args['body']);
    $headers .= PHP_EOL . $r[0];
    $body = $r[1];

    if (mail($to, $subject, $body, $headers)) {
        return 0;
    } else {
        return 5;
    }
}

function email2_helper($body, $top = true) {
    if (is_string($body)) {
        if (substr($body, 0, 1) == '<') {
            return email2_helper(array('type' => 'html', 'body' => $body), $top);
        } else {
            return email2_helper(array('type' => 'text', 'body' => $body), $top);
        }
    }
    # now we can assume $body is an associative array
    # defaults:
    $type = 'application/octet-stream';
    $mime = false;
    $boundary = null;
    $disposition = null;
    $charset = false;
    # process 'type' first, because it sets defaults for others
    if (isset($body['type'])) {
        $type = $body['type'];
        if ($type === 'text') {
            $type = 'text/plain';
            $charset = true;
        } elseif ($type === 'html') {
            $type = 'text/html';
            $charset = true;
        } elseif ($type === 'alternative' || $type === 'alternatives') {
            $mime = true;
            $type = 'multipart/alternative';
        } elseif ($type === 'mixed') {
            $mime = true;
            $type = 'multipart/mixed';
        }
    }
    if (isset($body['disposition'])) {
        $disposition = $body['disposition'];
    }
    if (isset($body['attachment'])) {
        if ($disposition == null) {
            $disposition = 'attachment';
        }
        $disposition .= "; filename=\"{$body['attachment']}\"";
        $type .= "; name=\"{$body['attachment']}\"";
    }
    # make headers
    $headers = array();
    if ($top && $mime) {
        $headers[] = 'MIME-Version: 1.0';
    }
    if ($mime) {
        $boundary = md5('5sd^%Ca)~aAfF0=4mIN' . rand() . rand());
        $type .= "; boundary=$boundary";
    }
    if ($charset) {
        $type .= '; charset=' . (isset($body['charset']) ? $body['charset'] : 'UTF-8');
    }
    $headers[] = "Content-Type: $type";
    if ($disposition !== null) {
        $headers[] = "Content-Disposition: {$disposition}";
    }

    $data = '';
    # return array, first el is headers, 2nd is body (php's mail() needs them separate)
    if ($mime) {
        foreach ($body['body'] as $sub_body) {
            $data .= "--$boundary" . PHP_EOL;
            $r = email2_helper($sub_body, false);
            $data .= $r[0] . PHP_EOL . PHP_EOL; # headers
            $data .= $r[1] . PHP_EOL . PHP_EOL; # body
        }
        $data .= "--$boundary--";
    } else {
        if(preg_match('/[^\x09\x0A\x0D\x20-\x7E]/', $body['body'])) {
            $headers[] = "Content-Transfer-Encoding: base64";
            $data .= chunk_split(base64_encode($body['body']));
        } else {
            $data .= $body['body'];
        }
    }
    return array(join(PHP_EOL, $headers), $data);
}

您可以尝试使用以下代码:

    $filename = 'myfile';
    $path = 'your path goes here';
    $file = $path . "/" . $filename;

    $mailto = 'mail@mail.com';
    $subject = 'Subject';
    $message = 'My message';

    $content = file_get_contents($file);
    $content = chunk_split(base64_encode($content));

    // a random hash will be necessary to send mixed content
    $separator = md5(time());

    // carriage return type (RFC)
    $eol = "\r\n";

    // main header (multipart mandatory)
    $headers = "From: name <test@test.com>" . $eol;
    $headers .= "MIME-Version: 1.0" . $eol;
    $headers .= "Content-Type: multipart/mixed; boundary=\"" . $separator . "\"" . $eol;
    $headers .= "Content-Transfer-Encoding: 7bit" . $eol;
    $headers .= "This is a MIME encoded message." . $eol;

    // message
    $body = "--" . $separator . $eol;
    $body .= "Content-Type: text/plain; charset=\"iso-8859-1\"" . $eol;
    $body .= "Content-Transfer-Encoding: 8bit" . $eol;
    $body .= $message . $eol;

    // attachment
    $body .= "--" . $separator . $eol;
    $body .= "Content-Type: application/octet-stream; name=\"" . $filename . "\"" . $eol;
    $body .= "Content-Transfer-Encoding: base64" . $eol;
    $body .= "Content-Disposition: attachment" . $eol;
    $body .= $content . $eol;
    $body .= "--" . $separator . "--";

    //SEND Mail
    if (mail($mailto, $subject, $body, $headers)) {
        echo "mail send ... OK"; // or use booleans here
    } else {
        echo "mail send ... ERROR!";
        print_r( error_get_last() );
    }

编辑14 - 6 - 2018

为更多的可读性在一些电子邮件提供商 使用

$body .= $eol。美元的消息。eol美元。eol美元;而且 $body .= $eol。美元的内容。eol美元。eol美元;