wp-mail-override.php

// An example wp_mail() override that you can place in your site's wp-config.php.
// Read the corresponding post https://www.itthinx.com/2021/09/06/wordpress-mail-debugging/

define( 'WP_DEBUG', true );
define( 'WP_DEBUG_LOG', true );
define( 'WP_DEBUG_DISPLAY', false );

function wp_mail( $to, $subject, $message, $headers = '', $attachments = array() ) {
	$output = sprintf(
		"\n\n" .
		"---------- Caught email via wp_mail() override in wp-config.php ---------- \n\n" .
		"To: %s\n\n" .
		"Subject: %s\n\n" .
		"Message: %s\n\n" .
		"Headers: %s\n\n" .
		"Attachments: %s\n\n" .
		"-------------------------------------------------------------------------- \n\n" .
		"\n\n",
		$to,
		$subject,
		$message,
		json_encode( $headers ),
		json_encode( $attachments )
	);
	error_log( $output );
	return true;
}