Hello there, @Work_2023. I'm here to provide details about the invoice attachments investigation.

We understand the inconvenience caused by this. For now, the status of this investigation is still going, and our Engineering Team is working on this matter to implement a solution to resolve this.

If you already contact our Support Team, you'll receive an email once the investigation is resolved. If not, I recommend contacting our  Support Team. They can add you to our notification list, and you'll receive an email notification once an update is available.

I’m also adding here an article that will guide you if you want to create your templates in QuickBooks Desktop. Create a custom email template.

Don't hesitate to reply anytime if you still have other  QuickBooks-related questions or clarifications. I'm more than happy to assist you. Stay safe!