Defer WooCommerce emails for a few minutes - Defer WooCommerce emails for a specified time after the normal delivery time. https://www.damiencarbery.com/2020/04/defer-woocommerce-emails-for-a-few-minutes/

wc-defer-order-emails.php

<?php
/*
Plugin Name: Defer WooCommerce emails for a few minutes (use Action Scheduler)
Plugin URI: https://www.damiencarbery.com/2020/04/defer-woocommerce-emails-for-a-few-minutes/
Description: Defer WooCommerce emails for a specified time after the normal delivery time. Use Action Scheduler instead of WP Cron. Call do_action() instead of remove_action() and calling trigger.
Author: Damien Carbery
Author URI: https://www.damiencarbery.com
Version: 0.11.20250528
*/


class DeferSendingWooCommerceEmails {
	private static $instance;
	private $default_defer_time;
	// An associative array to match $email_id with email class, to allow for the deferring of different emails.
	private $email_id_to_defer;
	
	private $debug_mode;


	// Returns an instance of this class. 
	public static function get_instance() {
		if ( null == self::$instance ) {
			self::$instance = new DeferSendingWooCommerceEmails();
		} 
		return self::$instance;
	}


	// Initialize the plugin variables.
	public function __construct() {
		$this->debug_mode = false;
		// Uncomment this to enable debug mode.
		//$this->debug_mode = true;

		$this->default_defer_time = 600; // Defer for 600 seconds (10 minutes).
		if ( $this->debug_mode ) {
			$this->default_defer_time = 60;  // Defer for 1 minute when debugging.
		}

		// Can add other email IDs and their defer times.
		// You can uncomment the add_action() with 'order_status_changed' function to find out the before and after status.
		// This is also the list of emails that will be deferred.
		$this->email_id_to_defer = array(
			'woocommerce_order_status_completed' =>  $this->default_defer_time,

			//'woocommerce_order_status_processing' =>  $this->default_defer_time,

			// Probably don't want to defer these emails but they are shown
			// here as a demo of a different defer time.			
			//'woocommerce_new_customer_note' => $this->default_defer_time,
			//'woocommerce_order_status_pending_to_on-hold' => $this->default_defer_time,  // New order
			//'woocommerce_order_status_pending_to_processing' => $this->default_defer_time,
			
			// Additional transitition-to-email class info from @djm56
			//'woocommerce_order_status_on-hold' => $this->default_defer_time,  // Order on hold.
			//'woocommerce_order_status_pending_to_on-hold' => $this->default_defer_time,  // Order on hold.
			//'woocommerce_order_status_cancelled_to_on-hold' => $this->default_defer_time,  // Order on hold.
			//'woocommerce_order_status_pending_to_on-hold' => $this->default_defer_time,  // Order on hold.
		);

		// Wait until other plugins loaded so that we can check for some specific plugins.
		add_action( 'plugins_loaded', array( $this, 'init' ) );
	}


	// Set up WordPress specfic actions.
	public function init() {
		// Use a filter to enable (or disable) debug mode.
		$this->debug_mode = apply_filters( 'DeferSendingWooCommerceEmails_debug_mode', $this->debug_mode );

		// Set all WooCommerce emails to be deferred.
		add_filter( 'woocommerce_defer_transactional_emails', '__return_true' );

		// Allow most emails to be sent as normal but prevent emails listed in $this->email_id_to_defer. Schedule them for a time in the future.
		add_filter( 'woocommerce_allow_send_queued_transactional_email', array( $this, 'whether_send_queued_wc_email' ), 10, 3 );

		// This is the scheduled function that will send the email.
		add_action( 'send_deferred_woocommerce_email', array( $this, 'send_deferred_woocommerce_email' ), 10, 2 );
		
		// If Custom Order Statuses for WooCommerce by Nuggethon is active (https://wordpress.org/plugins/custom-order-statuses-for-woocommerce/)
		// attached to some additional hooks to defer new order status emails.
		if ( class_exists( 'WOOCOS_Email_Manager' ) ) {
			add_action( 'woocommerce_order_status_changed', array( $this, 'defer_woocos_emails' ), 1, 3 );
			//add_action( 'woocommerce_order_status_changed_to_woocos', array( $this, 'woocos_email_trigger' ), 5, 4 );
			// This is the scheduled function that will send the WooCOS emails.
			add_action( 'send_deferred_woocos_mails', array( $this, 'send_deferred_woocos_mails' ), 10, 3 );
		}

		// DEBUG: Add the order modification time and current time to prove that the email was intentionally delayed.
		if ( $this->debug_mode ) {
			add_action( 'woocommerce_email_order_details', array( $this, 'add_defer_length_info_to_order_email' ), 5, 4 ); 
		}
		
		// Uncomment this to log the before and after statuses so you know what ones
		// to add to the $this->email_id_to_defer array.
		//add_action('woocommerce_order_status_changed', array( $this, 'order_status_changed' ), 10, 4); 
	}

	// Log the before and after status to discover which one to add to $this->email_id_to_defer array.
	public function order_status_changed( $id, $from, $to, $order ) {
		if ( $this->debug_mode ) {
			error_log( 'Order ID: ' . $id );
			error_log( 'Status from: ' . $from );
			error_log( 'Status to: ' . $to );
		}
	}

	
	private function get_email_defer_time( $filter ) {
		if ( array_key_exists( $filter, $this->email_id_to_defer ) ) {
			return $this->email_id_to_defer[ $filter ];
		}

		return $this->default_defer_time;
	}
	
	
	public function whether_send_queued_wc_email( $true, $filter, $args ) {
		if ( $this->debug_mode ) {
			error_log( 'woocommerce_allow_send_queued_transactional_email $filter: ' . var_export( $filter, true ) );
			error_log( 'woocommerce_allow_send_queued_transactional_email order_number: ' . var_export( $args[ 0 ], true ) );
			error_log( 'woocommerce_allow_send_queued_transactional_email defer this email? ' . array_key_exists( $filter, $this->email_id_to_defer ) ? 'Yes' : 'No' );
		}
		
		if ( array_key_exists( $filter, $this->email_id_to_defer ) ) {
			// TODO: Consider verifying that $args[0] is a valid order number.
			//$order = wc_get_order( $args[ 0 ] );
			//$action_args = array( 'filter' => $filter, 'args' => $args );

			// Call Action Scheduler instead of WP Cron. Args will be filter and $args.
			$event_id = as_schedule_single_action( time() + $this->get_email_defer_time( $filter ), 'send_deferred_woocommerce_email', array( $filter, $args ) );

			//$order_num = $args[ 0 ];
			//error_log( sprintf( 'woocommerce_allow_send_queued_transactional_email: Defer a %s email for order: %s for %d seconds (event ID: %d).', $filter, $order_num, $this->get_email_defer_time( $filter ), $event_id ) );

			return false;
		}

		if ( $this->debug_mode ) {
			error_log( 'woocommerce_allow_send_queued_transactional_email: Ok to send email.' );
		}

		return $true;
	}


	// Send the deferred email for order $order_id.
	public function send_deferred_woocommerce_email( $filter, $args = array() ) {
		if ( $this->debug_mode ) {
			error_log( 'send_deferred_woocommerce_email for $filter: ' . $filter );
			error_log( 'send_deferred_woocommerce_email for $args: ' . var_export( $args, true ) );
		}

		// Use same code as WC_Emails::send_queued_transactional_email() in woocommerce/includes/class-wc-emails.php
		WC_Emails::instance();
		// Ensure gateways are loaded in case they need to insert data into the emails.
		WC()->payment_gateways();
		WC()->shipping();

		do_action_ref_array( $filter . '_notification', $args );
	}
	
	
	public function woocos_email_trigger( $order_id, $custom_order_status, $new_status, $posted ) {
		if ( $this->debug_mode ) {
			error_log( '$order_id:' . var_export( $order_id, true ) );
			error_log( '$custom_order_status:' . var_export( $custom_order_status, true ) );
			error_log( '$new_status:' . var_export( $new_status, true ) );
			error_log( '$posted:' . var_export( $posted, true ) );
		}
	}


	// Remove the WooCOS function and schedule it to be called it later.
	public function defer_woocos_emails( $order_id, $old_status, $new_status ) {
		remove_action('woocommerce_order_status_changed', 'woocos_add_custom_order_status_actions', 10, 3);

		$event_id = as_schedule_single_action( time() + $this->get_email_defer_time( 'woocos' ), 'send_deferred_woocos_mails', array( $order_id, $old_status, $new_status ) );
	}


	public function send_deferred_woocos_mails( $order_id, $old_status, $new_status ) {
		woocos_add_custom_order_status_actions( $order_id, $old_status, $new_status );
	}


	// This is an experimental function to add the date/time the order was modified and
	// the date/time the email was sent into email - to demonstrate that the deferring code worked.
	public function add_defer_length_info_to_order_email( $order, $sent_to_admin, $plain_text, $email ) {
		if ( !is_object( $email ) ) { return; }  // Ensure $email is an object before testing $email->id.

		if ( 'customer_completed_order' == $email->id ) {
			if ( $plain_text ) {
				printf( '%sThe order was modified at %s and email sent at %s.', "\n", $order->get_date_modified(), current_time( 'mysql' ) );
			}
			else {
				printf( '<p>The order was modified at <strong>%s</strong> and email sent at <strong>%s</strong>.</p>', $order->get_date_modified(), current_time( 'mysql' ) );
			}
		}
	}
}

$DeferSendingWooCommerceEmails = new DeferSendingWooCommerceEmails();

I have solved mine the problem! I commented out the hooks for debugging, because these actions are missing in the desired email. Message ID is"woocommerce_created_customer".

I have solved mine the problem! I commented out the hooks for debugging, because these actions are missing in the desired email. Message ID is"woocommerce_created_customer".
Did you add 'woocommerce_created_customer' to the $this->email_id_to_defer array?

Where should this code be placed?

Where should this code be placed?

@esachs4 : The code is a standalone plugin. You can download the raw file and upload it to wp-content/plugins and then activate it. I made a demo video at: https://www.damiencarbery.com/2018/10/how-to-use-my-code-snippets/

Hello,
I have installed the plugin and i see on the log that the plugin start.
I also see the print of the function order_status_changed regarding the order detail
but i don't see any scheduled action and there is no delay on the mail.
I also installed the plugin action-scheduler.
Any idea?
Thank you!

Hello, I have installed the plugin and i see on the log that the plugin start. I also see the print of the function order_status_changed regarding the order detail but i don't see any scheduled action and there is no delay on the mail. I also installed the plugin action-scheduler. Any idea? Thank you!

Action Scheduler is part of WooCommerce so you do not need to install anything extra. I will test the plugin to verify that it works with the latest version of WooCommerce and then reply to you.

Thank you for the quick reply.
Ok got it!
Another think, i'm using YayMail for customize the mail, can this effect?
I have tried without that plugin but no difference.

Thank you for the quick reply. Ok got it! Another think, i'm using YayMail for customize the mail, can this effect? I have tried without that plugin but no difference.

Yes, YayMail could have an effect. I will look at this.

I did try my code this morning and it works. I updated the code to 0.10.20250528 to make it easier to turn on debug mode.

This screenshot shows that the Order Complete email was delayed about 60 seconds (the defer time in debug mode is 60 secs).

Thank you for the quick reply. Ok got it! Another think, i'm using YayMail for customize the mail, can this effect? I have tried without that plugin but no difference.

I spent a lot of time today debugging the code but it actually works without having made any changes. I don't know why it wasn't working earlier today. Bizarre.

I did a little more code tidying and it is now version 0.11.20250528. Please try it out.
You can uncomment line 34 to enable debug mode and then look in your wp-content/debug.log or server error_log file for messages.
//$this->debug_mode = true;

Hello,
Thank you so much for your effort.
I have tried the last version of the plugin: installed and activated.
But unfortunately still not working. YayMail is disabled
i have enabled the debug mode, but from the log i don't see any print from the plugin.
So i have added a couple of print :

and i see in the log

but for the rest no log.
Probably there is some other thing clashing with the plugin
Thank you

Hello, Thank you so much for your effort. I have tried the last version of the plugin: installed and activated. But unfortunately still not working. YayMail is disabled i have enabled the debug mode, but from the log i don't see any print from the plugin. So i have added a couple of print :

and i see in the log

but for the rest no log. Probably there is some other thing clashing with the plugin Thank you

Yes, I think that there must be something else clashing. When debug mode is enabled there should be a number of messages in the log.
Please email me at [email protected] so we can investigate this.