Mistakenly received confidential e-mail detailing unethical behavior

Question

I was a little surprised to receive a confusing e-mail from someone relatively high up in our organization who I hadn't had any contact with before. The e-mail was part of a long chain of forwards and replies detailing various surveying information for the plat of land my company owns, along with plans for current and future improvements on that land. The e-mails were all clearly marked as confidential. It didn't make any sense to me at first, until looking down the email thread I realized that the e-mail was actually intended for someone with my exact name at an outside company.

Normally, I'd just ignore said e-mail and probably respond to the sender letting them know they sent it to the wrong address. However, while perusing the documents that were sent to me (in the course of figuring out what they were) I noticed a member of my company make a statement that the city's information for the purpose of tax assessment was incorrect (I think they had not updated the improved land acreage or something similar), and detailing ways to continue to make sure that the city doesn't find out in the hopes of saving the company $80k a year (the estimated tax difference).

This doesn't seem like illegal behavior, but it does seem a little unethical, and I'm not sure what I should do. Presumably I would just pretend I never saw anything and privately e-mail the original sender. Unfortunately the conversation has quickly continued on, and I'm now "on the list" so to speak, and receiving further updates about this situation, from both internal and external people, including a few who I think are legal counsel. I also feel a little odd essentially drawing attention to myself, when I know this is information I'm not supposed to have.

How should I handle this?

NOTE: I realize there are a few other mistaken e-mail questions on the site, but I believe this to be different given the nature of the information I was sent.

Answer 1

Treat it like any other misdirected email. Reply to whoever got you involved, let them know that you're not the Mordred that they intended to email. Don't mention any of the content. And do it sooner rather than later-- if you've watched the thread for days, it's going to look like you're snooping when you fess up.

Realistically, unless you're an expert in taxation, it is likely to be very difficult to judge from an email thread whether a group of people are acting ethically to minimize taxes by avoiding certain actions that trigger taxable events or whether those people are discussing unethical or illegal ways to structure the transaction to avoid taxes. There are already attorneys and outside people in the conversation that have an obligation to bring up that sort of thing. I'd always err on the side of giving other people the benefit of the doubt that they're planning to behave responsibly.

If you are convinced that the company is behaving poorly and that the city has made a mistake in assessing the tax, you could send an anonymous note to the city alerting them that there may be an issue. Generally, though, the tax bureaucracy isn't going to jump to action to investigate that sort of charge. Plus, there is a decent chance that it's not an issue or not something the city can correct until the next assessment (which may not happen for a while if the deal is structured correctly).