通过Zend Mail发送邮件失败，DKIM签名失败，并在qq.com中发送垃圾邮件

Question

I am struggling with sending email with ZF2. The thing is they all work well in other mail clients I have tested but in qq.com all mail goes to spam folder. Here is the code I am using to send the mail:

$mailTransportModel = $sl->get('MailTransportModel');

$transport = $mailTransportModel->getMailTransport($parameters['api_key']);
$messageIdHost = $config['mailServers'][$parameters['api_key']]['messageIdHost'];

$mail = new Zend\Mail\Message();
$mail->addTo($parameters['to'])
    ->setFrom($parameters['from_email'], $parameters['from_name'])
    ->setSubject(CommonLib::assignTemplateVariables($parameters['template']['subject'], $parameters['context_variables']));

if(!empty($parameters['replyto_email'])) {
    if(!empty($parameters['replyto_name'])) {
    $mail->addReplyTo($parameters['replyto_email'], $parameters['replyto_name']);
    } else {
    $mail->addReplyTo($parameters['replyto_email']);
    }
}

$headers = $mail->getHeaders();

$messageId = sha1($config['salt'] . microtime());
$headers->addHeaderLine('Message-Id', "<" . $messageId . "@" . $messageIdHost . ">");

$html = new Part(CommonLib::assignTemplateVariables($parameters['template']['body'], $parameters['context_variables']));

$body = new Zend\Mime\Message();

// Create HTML part
$html          = new Part(CommonLib::assignTemplateVariables($parameters['template']['body'], $parameters['context_variables']));
$html->type    = Mime::TYPE_HTML;
$html->charset = 'utf-8';

// Create plain text part
$stripTagsFilter   = new \Zend\Filter\StripTags();
$textContent       = str_ireplace(array("<br />", "<br>"), "\r\n", CommonLib::assignTemplateVariables($parameters['template']['body'], $parameters['context_variables']));
$textContent       = $stripTagsFilter->filter($textContent);
$textPart          = new Zend\Mime\Part($textContent);
$textPart->type    = Mime::TYPE_TEXT;

// Create separate alternative parts object
$alternatives           = new Zend\Mime\Message();
$alternatives->setParts(array($textPart, $html));
$alternativesPart       = new Zend\Mime\Part($alternatives->generateMessage());
$alternativesPart->type = Mime::MULTIPART_ALTERNATIVE . "; \n boundary=\"" . $alternatives->getMime()->boundary() . "\"";
$body->addPart($alternativesPart);
$mail->setBody($body);
$mail->setEncoding("UTF-8");

$headers->get('content-type')->setType('multipart/alternative');

$transport->send($mail);

And here are example headers from the recieved mail:

Delivered-To: CUSTOMER_EMAIL
Received: by SOMEIP with SMTP id e9csp1233069oid;
        Thu, 2 Apr 2015 07:35:03 -0700 (PDT)
X-Received: by SOMEIP with SMTP id eg3mr25568854wib.11.1427985302528;
        Thu, 02 Apr 2015 07:35:02 -0700 (PDT)
Return-Path: <something@something.com>
Received: from something (something. [OTHERIP])
        by mx.google.com with ESMTP id ew1si9167339wjb.35.2015.04.02.07.35.01
        for <CUSTOMER_EMAIL>;
        Thu, 02 Apr 2015 07:35:02 -0700 (PDT)
Received-SPF: pass (google.com: domain of something@something.com designates OTHERIP as permitted sender) client-ip=OTHERIP;
Authentication-Results: mx.google.com;
       spf=pass (google.com: domain of something@something.com designates OTHERIP as permitted sender) smtp.mail=something@something.com
Message-ID: <551d5394.4164c20a.5989.fffff01fSMTPIN_ADDED_BROKEN@mx.google.com>
X-Google-Original-Message-ID: =?UTF-8?Q?<LONGID@something.com>?=
Received: from HOST (OTHERHOST [SOMEIP])
    by HOST (Postfix) with ESMTP id 834E3195
    for <CUSTOMER_EMAIL>; Thu,  2 Apr 2015 17:35:01 +0300 (EEST)
X-DKIM: Sendmail DKIM Filter v2.8.3 HOST 834E3196
Date: Thu, 02 Apr 2015 17:35:01 +0300
To: CUSTOMER_EMAIL
From: =?UTF-8?Q?SOMETHING.COM?= <something@something.com>
Subject: =?UTF-8?Q?Daily=20Statement?=
MIME-Version: 1.0
Content-Type: multipart/alternative;
 boundary="=_c802aad96623e4d95c320e2cbceca602"
Content-Transfer-Encoding: =?UTF-8?Q?8bit?=
Sender: 

This is a message in Mime Format.  If you see this, your mail reader does not support this format.

--=_c802aad96623e4d95c320e2cbceca603
Content-Type: text/plain
Content-Transfer-Encoding: 8bit

<SOME HTML THINGS HERE>

--=_c802aad96623e4d95c320e2cbceca603--

What I notice is the DKIM signature failing... I suspect it might be from the empty Sender: header line but I have tried couple of things but none could remove it...

Thank you in advance!

Answer 1

Whew, finally I have found a solution to my problem. It turns out that my version of ZF2 is far too old. In fact it is 2.2.4. The thing is that after I pass the email message to the transport, Zend internally (Smtp.php class, prepareHeaders() function) clones the Headers object and, for some reason, removes the Bcc header. Not only that but it also adds the empty Sender header (since I have not set any value for it in the client code). Therefore, after passing the message to Postfix it has an empty Sender: header which it cannot be parsed in DKIM-filter. The PHP-side solution was to add a value for the Sender: header while constructing the message itself:

$mail->addTo($parameters['to'])
    ->setFrom($parameters['from_email'], $parameters['from_name'])
    ->setSubject(CommonLib::assignTemplateVariables($parameters['template']['subject'], $parameters['context_variables']))
    ->setSender($parameters['from_email'], $parameters['from_name']);

The final touch was to let the DKIM-filter know that the hosts, from which the emails were sent, were trusted.

It took me a good while to figure this out. I hope it will be useful for someone else :)