Add List-Unsubscribe header to emails [MAILPOET-793]

Amazon SES supports custom headers only via 'SendRawEmail' action
MailPoet Sending Service doesn't support custom headers yet

lib/Mailer/Mailer.php

@@ -2,6 +2,7 @@
 namespace MailPoet\Mailer;
 
 use MailPoet\Models\Setting;
+use MailPoet\Subscription\Url as SubscriptionUrl;
 
 if(!defined('ABSPATH')) exit;
 require_once(ABSPATH . 'wp-includes/pluggable.php');
@@ -29,8 +30,9 @@ class Mailer {
   }
 
   function send($newsletter, $subscriber) {
+    $extra_params = $this->getExtraParams($newsletter, $subscriber);
     $subscriber = $this->formatSubscriberNameAndEmailAddress($subscriber);
-    return $this->mailer_instance->send($newsletter, $subscriber);
+    return $this->mailer_instance->send($newsletter, $subscriber, $extra_params);
   }
 
   function buildMailer() {
@@ -166,6 +168,12 @@ class Mailer {
     return sprintf('=?utf-8?B?%s?=', base64_encode($name));
   }
 
+  function getExtraParams($newsletter, $subscriber) {
+    $extra_params = array();
+    $extra_params['unsubscribe_url'] = SubscriptionUrl::getUnsubscribeUrl($subscriber);
+    return $extra_params;
+  }
+
   static function formatMailerConnectionErrorResult($error_message) {
     return array(
       'response' => false,

lib/Mailer/Methods/AmazonSES.php

@@ -18,6 +18,7 @@ class AmazonSES {
   public $sender;
   public $reply_to;
   public $return_path;
+  public $message;
   public $date;
   public $date_without_time;
   private $available_regions = array(
@@ -48,10 +49,10 @@ class AmazonSES {
     $this->date_without_time = gmdate('Ymd');
   }
 
-  function send($newsletter, $subscriber) {
+  function send($newsletter, $subscriber, $extra_params = array()) {
     $result = wp_remote_post(
       $this->url,
-      $this->request($newsletter, $subscriber)
+      $this->request($newsletter, $subscriber, $extra_params)
     );
     if(is_wp_error($result)) {
       return Mailer::formatMailerConnectionErrorResult($result->get_error_message());
@@ -66,27 +67,61 @@ class AmazonSES {
     return Mailer::formatMailerSendSuccessResult();
   }
 
-  function getBody($newsletter, $subscriber) {
+  function getBody($newsletter, $subscriber, $extra_params = array()) {
+    $this->message = $this->createMessage($newsletter, $subscriber, $extra_params);
     $body = array(
-      'Action' => 'SendEmail',
+      'Action' => 'SendRawEmail',
       'Version' => '2010-12-01',
-      'Destination.ToAddresses.member.1' => $subscriber,
       'Source' => $this->sender['from_name_email'],
-      'ReplyToAddresses.member.1' => $this->reply_to['reply_to_name_email'],
-      'Message.Subject.Data' => $newsletter['subject'],
-      'ReturnPath' => $this->return_path
+      'RawMessage.Data' => $this->encodeMessage($this->message)
     );
-    if(!empty($newsletter['body']['html'])) {
-      $body['Message.Body.Html.Data'] = $newsletter['body']['html'];
-    }
-    if(!empty($newsletter['body']['text'])) {
-      $body['Message.Body.Text.Data'] = $newsletter['body']['text'];
-    }
     return $body;
   }
 
-  function request($newsletter, $subscriber) {
-    $body = array_map('urlencode', $this->getBody($newsletter, $subscriber));
+  function createMessage($newsletter, $subscriber, $extra_params = array()) {
+    $message = \Swift_Message::newInstance()
+      ->setTo($this->processSubscriber($subscriber))
+      ->setFrom(array(
+          $this->sender['from_email'] => $this->sender['from_name']
+        ))
+      ->setSender($this->sender['from_email'])
+      ->setReplyTo(array(
+          $this->reply_to['reply_to_email'] =>  $this->reply_to['reply_to_name']
+        ))
+      ->setReturnPath($this->return_path)
+      ->setSubject($newsletter['subject']);
+    if(!empty($extra_params['unsubscribe_url'])) {
+      $headers = $message->getHeaders();
+      $headers->addTextHeader('List-Unsubscribe', '<' . $extra_params['unsubscribe_url'] . '>');
+    }
+    if(!empty($newsletter['body']['html'])) {
+      $message = $message->setBody($newsletter['body']['html'], 'text/html');
+    }
+    if(!empty($newsletter['body']['text'])) {
+      $message = $message->addPart($newsletter['body']['text'], 'text/plain');
+    }
+    return $message;
+  }
+
+  function encodeMessage(\Swift_Message $message) {
+    return base64_encode($message->toString());
+  }
+
+  function processSubscriber($subscriber) {
+    preg_match('!(?P<name>.*?)\s<(?P<email>.*?)>!', $subscriber, $subscriber_data);
+    if(!isset($subscriber_data['email'])) {
+      $subscriber_data = array(
+        'email' => $subscriber,
+      );
+    }
+    return array(
+      $subscriber_data['email'] =>
+        (isset($subscriber_data['name'])) ? $subscriber_data['name'] : ''
+    );
+  }
+
+  function request($newsletter, $subscriber, $extra_params = array()) {
+    $body = array_map('urlencode', $this->getBody($newsletter, $subscriber, $extra_params));
     return array(
       'timeout' => 10,
       'httpversion' => '1.1',

lib/Mailer/Methods/MailPoet.php

@@ -17,7 +17,7 @@ class MailPoet {
     $this->reply_to = $reply_to;
   }
 
-  function send($newsletter, $subscriber) {
+  function send($newsletter, $subscriber, $extra_params = array()) {
     $message_body = $this->getBody($newsletter, $subscriber);
     $result = wp_remote_post(
       $this->url,

lib/Mailer/Methods/PHPMail.php

@@ -20,9 +20,9 @@ class PHPMail {
     $this->mailer = $this->buildMailer();
   }
 
-  function send($newsletter, $subscriber) {
+  function send($newsletter, $subscriber, $extra_params = array()) {
     try {
-      $message = $this->createMessage($newsletter, $subscriber);
+      $message = $this->createMessage($newsletter, $subscriber, $extra_params);
       $result = $this->mailer->send($message);
     } catch(\Exception $e) {
       return Mailer::formatMailerSendErrorResult($e->getMessage());
@@ -39,7 +39,7 @@ class PHPMail {
     return \Swift_Mailer::newInstance($transport);
   }
 
-  function createMessage($newsletter, $subscriber) {
+  function createMessage($newsletter, $subscriber, $extra_params = array()) {
     $message = \Swift_Message::newInstance()
       ->setTo($this->processSubscriber($subscriber))
       ->setFrom(array(
@@ -51,6 +51,10 @@ class PHPMail {
         ))
       ->setReturnPath($this->return_path)
       ->setSubject($newsletter['subject']);
+    if(!empty($extra_params['unsubscribe_url'])) {
+      $headers = $message->getHeaders();
+      $headers->addTextHeader('List-Unsubscribe', '<' . $extra_params['unsubscribe_url'] . '>');
+    }
     if(!empty($newsletter['body']['html'])) {
       $message = $message->setBody($newsletter['body']['html'], 'text/html');
     }

lib/Mailer/Methods/SMTP.php

@@ -34,9 +34,9 @@ class SMTP {
     $this->mailer = $this->buildMailer();
   }
 
-  function send($newsletter, $subscriber) {
+  function send($newsletter, $subscriber, $extra_params = array()) {
     try {
-      $message = $this->createMessage($newsletter, $subscriber);
+      $message = $this->createMessage($newsletter, $subscriber, $extra_params);
       $result = $this->mailer->send($message);
     } catch(\Exception $e) {
       return Mailer::formatMailerSendErrorResult($e->getMessage());
@@ -60,7 +60,7 @@ class SMTP {
     return \Swift_Mailer::newInstance($transport);
   }
 
-  function createMessage($newsletter, $subscriber) {
+  function createMessage($newsletter, $subscriber, $extra_params = array()) {
     $message = \Swift_Message::newInstance()
       ->setTo($this->processSubscriber($subscriber))
       ->setFrom(array(
@@ -72,6 +72,10 @@ class SMTP {
         ))
       ->setReturnPath($this->return_path)
       ->setSubject($newsletter['subject']);
+    if(!empty($extra_params['unsubscribe_url'])) {
+      $headers = $message->getHeaders();
+      $headers->addTextHeader('List-Unsubscribe', '<' . $extra_params['unsubscribe_url'] . '>');
+    }
     if(!empty($newsletter['body']['html'])) {
       $message = $message->setBody($newsletter['body']['html'], 'text/html');
     }

lib/Mailer/Methods/SendGrid.php

@@ -17,10 +17,10 @@ class SendGrid {
     $this->reply_to = $reply_to;
   }
 
-  function send($newsletter, $subscriber) {
+  function send($newsletter, $subscriber, $extra_params = array()) {
     $result = wp_remote_post(
       $this->url,
-      $this->request($newsletter, $subscriber)
+      $this->request($newsletter, $subscriber, $extra_params)
     );
     if(is_wp_error($result)) {
       return Mailer::formatMailerConnectionErrorResult($result->get_error_message());
@@ -35,7 +35,7 @@ class SendGrid {
     return Mailer::formatMailerSendSuccessResult();
   }
 
-  function getBody($newsletter, $subscriber) {
+  function getBody($newsletter, $subscriber, $extra_params = array()) {
     $body = array(
       'to' => $subscriber,
       'from' => $this->sender['from_email'],
@@ -43,6 +43,13 @@ class SendGrid {
       'replyto' => $this->reply_to['reply_to_email'],
       'subject' => $newsletter['subject']
     );
+    $headers = array();
+    if(!empty($extra_params['unsubscribe_url'])) {
+      $headers['List-Unsubscribe'] = '<' . $extra_params['unsubscribe_url'] . '>';
+    }
+    if($headers) {
+      $body['headers'] = json_encode($headers);
+    }
     if(!empty($newsletter['body']['html'])) {
       $body['html'] = $newsletter['body']['html'];
     }
@@ -56,8 +63,8 @@ class SendGrid {
     return 'Bearer ' . $this->api_key;
   }
 
-  function request($newsletter, $subscriber) {
-    $body = $this->getBody($newsletter, $subscriber);
+  function request($newsletter, $subscriber, $extra_params = array()) {
+    $body = $this->getBody($newsletter, $subscriber, $extra_params);
     return array(
       'timeout' => 10,
       'httpversion' => '1.1',