Customizable Invoice Naming

We’ve run into some issues with the generated invoice PDFs. Every emailed invoice is attached as "invoice.pdf", no matter the guest or reservation. While this is usually fine, some OTAs that use masked or relay email addresses will reject messages if an attachment with that filename has been sent before (even if it’s for a different guest). As a result, many folios fail to deliver unless we wait for guests to provide a personal email.

It would be super helpful if invoice PDFs could use dynamic file names based on reservation data, such as confirmation numbers, guest names, or stay dates. If full customization isn’t possible, even appending a confirmation or folio number by default would help tremendously.

Thanks so much everyone!