Hello @stathisstr,
Please note that if those custom emails are not WooCommerce email notifications, the Attach to setting, that you find under WooCommerce > PDF Invoices > Document > Invoice, will not fetch those custom emails by default.
However, if you do see your custom emails there, and you have selected them, but they are still failing, could you check the WooCommerce logs to see if there are errors with the wpo-wcpdf or fatal-errors prefix? If so, please share the logs with us. You’ll find the logs under WooCommerce > Status > Logs. See Where to find error logs
Hi @stathisstr,
Since we haven’t heard back from you in the last two weeks, we’re assuming you solved this issue, so I’ll go ahead and mark this ticket as Resolved.
Feel free to reply to this topic is you still need help with this, or open a new topic if you have any other questions!