I work at a big company and get sales, marketing, press, and customer inquiries ALL THE TIME, at my PERSONAL email address (which is easier to find than my work address). There is absolutely nothing I can do to help you if you contact me directly because company policy forbids it, official channels exist for a reason.

If a company suffers from people contacting the wrong people, I think the solution is to make it easier to contact the right people.

Also, you could just inform the customer to resend the info to the official channel and make sure someone is actually keeping an eye out for it.