How can I add the sku code in [commerce-order:commerce-email-order-items] While the shortcode [commerce-order:commerce-email-order-items] is used to send several commerce emails, it does not includes SKU code. How can I add sku code or edit the output of [commerce-order:commerce-email-order-items]
Some tokens are generated by code others by views. This token is generated by code

So edit commerce_email.module and around line 420 you will see commerce_email_order_items function here you can add the sku.

Take in mind that this is not an ideal solution See hook_tokens_alter