Postmark Mailing in Silverstripe 4.5

README.md

Sending Emails via Postmark in Silverstripe 4

Silverstripe 4 uses an older version of Swift Mailer (v5) not v6 so you'll find the latest Postmark SDK won't work out of the box. You'll receive something like the following when you come to do $email->send()

ERROR [Notice]: Object of class GuzzleHttp\Psr7\Response could not be converted to int
Line 45 in framework/src/Control/Email/SwiftMailer.php

Not to fear! With a bit of configuration and a wrapper class we can get this to work. Apply the email.yml config to your project and but the PostmarkMailTransport.php class in your project code.

composer.sh

composer require wildbit/swiftmailer-postmark ^2

email.yml

---
Name: projectemailconfig
After:
  - '#emailconfig'
---
SilverStripe\Core\Injector\Injector:
  Swift_Transport:
    class: PostmarkMailTransport
    constructor:
      0: '{{ your postmark key }}'

PostmarkMailTransport.php

<?php

use Psr\Log\LoggerInterface;
use SilverStripe\Control\Email\Email;
use SilverStripe\Control\Director;
use SilverStripe\Core\Environment;
use SilverStripe\Core\Injector\Injector;

class PostmarkMailTransport extends \Postmark\Transport
{
    public function send(Swift_Mime_Message $message, &$failedRecipients = null)
    {
        if (!$message->getFrom()) {
            $message->setFrom(Email::config()->send_all_emails_from);
        }

        if (defined('SS_SEND_ALL_EMAILS_TO')) {
            // override sender
            $message->setTo(SS_SEND_ALL_EMAILS_TO);
        } elseif ($t = Environment::getEnv('SS_SEND_ALL_EMAILS_TO')) {
            // send
            $message->setTo($t);
        } elseif (Director::isDev() || Director::isTest()) {
            // prevent emailing to everyone
            $message->setTo(Email::config()->admin_email);
        }

        $result = parent::send($message, $failedRecipients);

        if ($result->getStatusCode() == 200) {
            return 1;
        } else {
            $err = sprintf(
                'Could not send Postmark Email: Error status %s - %s %s',
                $result->getStatusCode(),
                $result->getReasonPhrase(),
                $result->getBody()->getContents()
            );

            Injector::inst()->get(LoggerInterface::class)->warning($err);

            if (Director::isDev()) {
                throw new Exception($err);
            }

            return 0;
        }

        return $result;
    }
}