But why do you consider this good practice? It's (unnecessarily?) frustrating for senders and poses a legal risk for recipients (the sender has the logs to prove that they sent the invoice, while the recipient doesn't have any record).
Regardless, there are always better options than silently discarding the whole email: delete attachments, erase everything that looks like a URL, even erase the whole message body, but please tell the recipient that you accepted an email and from whom.