So many awesome answers. this is something that i'm afraid of experiencing myself, so it's good to know that people shouldn't stand by when wage gaps happen.

I think you should tell the HR, and then return the salary.

Collin, I apologize that I'm a little late to this rodeo. I can't speak for all companies but I know how I work. My emails are on dedicated lists and each group list is for a different reason. If I was asked to provide a list of employee salaries it would be for a specific reason, either termination or promotion. I happen to live in a state that has just hiked the minimum wage. Depending on the employee's work location companies are required to boost current employees to the local minimum wage which will be $15 per hour in three years for urban locations and $15 per hour in five years for outlying. We have been producing reports to determine a cost effective method of boosting all nonconforming salaries across the board to meet the three/five year deadlines. The salary gap doesn't concern me as much as the reason for this list and who should have actually been cc'd. Quietly let your manager know that you have the proprietary information. They will contact the originator so that the sender can immediately correct their email list. No harm no foul for them. I would suggest updating your resume just in case. I hope this helps.

HI Collin,

I agree with the others' responses: go to your manager and - politely and with discretion - report this. It is not fair to you.

Frank

You write this as if you are in a current corporate position but your onlineresume shows your last position was almost a year ago. What gives? You just trying to stir up controversy andget some ofus to respond to a hypothetical situation? OK, here goes: If (big if, in my opinion - since I doubt the reality of your "question") you were actually in such a position and IF HR might inquire (unlikely) - just deny you ever got such a thing. Don't do anything that might "rub someone's nose in it"

Definitely report it! Most companies track everything you do on your computer and e-mail, so they are going to eventually see it. It is better to report it, especially when you did not do anything wrong. Usually if you don't say something, they will become suspicious. Two people at my last job were both fired because someone e-mailed out test answers and the person who received opened the e-mail and never reported it. If it was reported, the person on the receiving end would never have gotten in trouble.

Hi Collin: I'm more concerned about the fact that you found out your coworkers are making more for the same job. This should absolutely be addressed, particularly if you have the same level of experience and skills as your coworkers. Rather than delete it, go to your manager and let them know HR sent this to you by mistake, and that you want to address this discrepancy. You weren't the one who made the mistake, so don't feel bad about it - if anything, it will be brought to HR's attention and they'll make sure they don't make the same mistake again.