woocommerce/templates/emails/plain/email-order-details.php

<?php
/**
 * Order details table shown in emails.
 *
 * This template can be overridden by copying it to yourtheme/woocommerce/emails/plain/email-order-details.php.
 *
 * HOWEVER, on occasion WooCommerce will need to update template files and you
 * (the theme developer) will need to copy the new files to your theme to
 * maintain compatibility. We try to do this as little as possible, but it does
 * happen. When this occurs the version of the template file will be bumped and
 * the readme will list any important changes.
 *
 * @see 	    https://docs.woocommerce.com/document/template-structure/
 * @author 		WooThemes
 * @package 	WooCommerce/Templates/Emails
 * @version     2.5.0
 */

if ( ! defined( 'ABSPATH' ) ) {
	exit;
}

do_action( 'woocommerce_email_before_order_table', $order, $sent_to_admin, $plain_text, $email );

echo strtoupper( sprintf( __( 'Order number: %s', 'woocommerce' ), $order->get_order_number() ) ) . "\n";
echo date_i18n( __( 'jS F Y', 'woocommerce' ), strtotime( $order->order_date ) ) . "\n";
echo "\n" . $order->email_order_items_table( array(
	'show_sku'    => $sent_to_admin,
	'show_image'  => false,
	'image_size'  => array( 32, 32 ),
	'plain_text'  => true
) );

echo "==========\n\n";

if ( $totals = $order->get_order_item_totals() ) {
	foreach ( $totals as $total ) {
		echo $total['label'] . "\t " . $total['value'] . "\n";
	}
}

if ( $sent_to_admin ) {
	echo "\n" . sprintf( __( 'View order: %s', 'woocommerce'), admin_url( 'post.php?post=' . $order->id . '&action=edit' ) ) . "\n";
}

do_action( 'woocommerce_email_after_order_table', $order, $sent_to_admin, $plain_text, $email );