Additional Header appears in email

Hello

Thanks for the great plugin.

I am using it to insert additional headers in my checkout page. However i have noticed that my additional headers are also being included in some woocommerce emails. Most notably the “your order is complete” email.

Has anyone else had a similar issue and knows the fix?

Thanks in advance.

https://ww.wp.xz.cn/plugins/woocommerce-checkout-manager/