For developers

How the module works

The module redirects WooCommerce emails to the Action Scheduler queue using the woocommerce_mail_callback filter:

add_filter( 'woocommerce_mail_callback', function() {
    return [ $this, 'add_job_to_queue' ];
} );

Sending process

1. Email capture - The module captures the wp_mail() call
2. Save to queue - Parameters are saved to wp_options
3. Schedule action - Action Scheduler schedules immediate sending
4. Asynchronous sending - Cron triggers the sending

Action Scheduler

Action for sending

// Action triggered when sending email
do_action( 'wpify_send_email', $hash );

Monitoring the queue

You can monitor the email queue in Tools → Scheduled Actions:

• Action: wpify_send_email
• Status: Pending / Complete / Failed

Data structure

Saving email parameters

// Parameters are saved as an option with a hash key
$args = [ $to, $subject, $message, $headers, $attachments ];
$hash = md5( json_encode( $args ) );
update_option( $hash, $args );

Loading and deletion

// When sending
$args = get_option( $hash );
delete_option( $hash ); // After successful loading

Example: Tracking sent emails

add_action( 'wpify_send_email', function( $hash ) {
    $args = get_option( $hash );

    if ( $args ) {
        error_log( sprintf(
            'Sending email to: %s, Subject: %s',
            $args[0], // to
            $args[1]  // subject
        ) );
    }
}, 5 ); // Priority before module

Example: Custom processing

add_action( 'wpify_send_email', function( $hash ) {
    $args = get_option( $hash );

    if ( ! $args ) {
        return;
    }

    // Custom logic before sending
    list( $to, $subject, $message, $headers, $attachments ) = $args;

    // For example, logging to a custom table
    global $wpdb;
    $wpdb->insert(
        $wpdb->prefix . 'email_log',
        [
            'to_email' => $to,
            'subject'  => $subject,
            'sent_at'  => current_time( 'mysql' ),
        ]
    );
}, 5 );

External cron

If you use DISABLE_WP_CRON, set up an external cron:

# Every minute
* * * * * wget -q -O - https://example.com/wp-cron.php?doing_wp_cron > /dev/null 2>&1

Or using WP-CLI:

* * * * * cd /path/to/wordpress && wp cron event run --due-now > /dev/null 2>&1

Action Scheduler vs WP Cron

The module uses Action Scheduler (part of WooCommerce), which is more reliable than standard WP Cron:

Feature	WP Cron	Action Scheduler
Triggering	On page visit	On visit + CLI
Logging	No	Yes
Management	Limited	Full
Scalability	Low	High