How to Send Magento 2 Order Confirmation Email After Payment Success

Default Magento automatically sends a order confirmation Email once the order is placed. But what if someone wants to send email after a successful payment completion from the third-party payment gateways in Magento 2 or what if the card is declined and payment fails? Unfortunately, Default Magento does not provide functionality of sending email after getting successful payment from third-party gateways so we have come up with custom code to send Email manually using event observer.

If you want to send the email only after the successful payment then you must write code in observer for checkout_onepage_controller_success_action event.

Create a simple method isEnable() using OrderIdentity.php to ensure that order confirmation email is not sent twice.

Register event under events.xml using below code
[Package_Name]\[Module_Name]\etc\frontend\events.xml

<?xml version="1.0"?>
 
<config xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="urn:magento:framework:Event/etc/events.xsd">
    <event name="checkout_onepage_controller_success_action">
        <observer name="checkout_onepage_controller_success_action_sendmail" instance="[Package_Name]\[Module_Name]\Observer\SendMailOnOrderSuccess" />
    </event>
</config>

Once the event is registered, create Observer class in the following file:
[Package_Name]\[Module_Name]\Observer\SendMailOnOrderSuccess.php

<?php
 
namespace [Package_Name]\[Module_Name]\Observer;
 
use Magento\Framework\Event\ObserverInterface;
 
class SendMailOnOrderSuccess implements ObserverInterface
{
    /**
     * @var \Magento\Sales\Model\OrderFactory
     */
    protected $orderModel;
 
    /**
     * @var \Magento\Sales\Model\Order\Email\Sender\OrderSender
     */
    protected $orderSender;
 
    /**
     * @var \Magento\Checkout\Model\Session $checkoutSession
     */
    protected $checkoutSession;
 
    /**
     * @param \Magento\Sales\Model\OrderFactory $orderModel
     * @param \Magento\Sales\Model\Order\Email\Sender\OrderSender $orderSender
     * @param \Magento\Checkout\Model\Session $checkoutSession
     *
     * @codeCoverageIgnore
     */
    public function __construct(
        \Magento\Sales\Model\OrderFactory $orderModel,
        \Magento\Sales\Model\Order\Email\Sender\OrderSender $orderSender,
        \Magento\Checkout\Model\Session $checkoutSession
    )
    {
        $this->orderModel = $orderModel;
        $this->orderSender = $orderSender;
        $this->checkoutSession = $checkoutSession;
    }
 
    /**
     * @param \Magento\Framework\Event\Observer $observer
     * @return void
     */
    public function execute(\Magento\Framework\Event\Observer $observer)
    {
        $orderIds = $observer->getEvent()->getOrderIds();
        if(count($orderIds))
        {
            $this->checkoutSession->setForceOrderMailSentOnSuccess(true);
            $order = $this->orderModel->create()->load($orderIds[0]);
            $this->orderSender->send($order, true);
        }
    }
}

After adding observer code, an email will be sent to customers on successful order payment. To avoid order duplication Email, we need to create a plugin using the di.xml file.
[Package_Name]\[Module_Name]\etc\di.xml

<?xml version="1.0"?>
 
<config xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="urn:magento:framework:ObjectManager/etc/config.xsd">
    <type name="Magento\Sales\Model\Order\Email\Container\OrderIdentity">
        <plugin name="change_is_enable_method" type="\[Package_Name]\[Module_Name]\Plugin\Sales\Order\Email\Container\OrderIdentityPlugin"/>
    </type>
</config>

And Lastly, you need to create another file along with ‘di.xml’ that is OrderIdentityPlugin.php to remove duplication of email.
[Package_Name]\[Module_Name]\Plugin\Sales\Order\Email\Container\ OrderIdentityPlugin.php

<?php

namespace [Package_Name]\[Module_Name]\Plugin\Sales\Order\Email\Container;

class OrderIdentityPlugin
{
    /**
     * @var \Magento\Checkout\Model\Session $checkoutSession
     */
    protected $checkoutSession;

    /**
     * @param \Magento\Checkout\Model\Session $checkoutSession
     *
     * @codeCoverageIgnore
     */
    public function __construct(
        \Magento\Checkout\Model\Session $checkoutSession
    )
    {
        $this->checkoutSession = $checkoutSession;
    }

    /**
     * @param \Magento\Sales\Model\Order\Email\Container\OrderIdentity $subject
     * @param callable $proceed
     * @return bool
     */
    public function aroundIsEnabled(\Magento\Sales\Model\Order\Email\Container\OrderIdentity $subject, callable $proceed)
    {
        $returnValue = $proceed();

        $forceOrderMailSentOnSuccess = $this->checkoutSession->getForceOrderMailSentOnSuccess();
        if(isset($forceOrderMailSentOnSuccess) && $forceOrderMailSentOnSuccess)
        {
            if($returnValue)
                $returnValue = false;
            else
                $returnValue = true;

            $this->checkoutSession->unsForceOrderMailSentOnSuccess();
        }

        return $returnValue;
    }
}

That’s it! Now start sending the order confirmation Emails to your customers only after the payment is successful! Hope this code will help you to send Order Confirmation Email to your Customers after Successful Payment Transaction. You can even use & customize this code according to your need.