People Fall for This?

Who actually falls for this email and opens the attachments?

Subject of email: Your Tracking # 235478914988
From: United Postal Service

UM ok if you really are going to try to get me to think I shipped something via the USPS perhaps you want to call the postal service by it's real name the *United States* Postal Service. Just Sayin'

Oh and BTW - I buy enough crap online that I know the USPS has never contacted me via email (except to confirm an address change I did online once). But even if I hadn't this email is so fake it's ridiculous!

Body of email:
Sorry, we were not able to deliver postal package you sent on November the 1st in time because the recipient s address is not correct.

Please print out the invoice copy attached and collect the package at our office.
If you do not receive package in ten days you will have to pay 36$ per day.

Your UPS

I'm not sure what is worse: the grammar or the content itself. If I don't 'receive' it they will charge $36? UM well since they are the 'postal service' it's kind of their job that I receive it (or rather the person I 'sent' it to does), perhaps if you don't 'pick up your package' or 'put the correct address on it' would have been slightly better. and really who's seen the post office sign anything 'yours UPS' oh and btw that acronym stands for 'united parcel service' and if they are trying to fake UPS, their tracking numbers always have a Z in them. But I'm back to - if you knew I send a package wouldn't you know my phone number or name?

What I don't understand is - who falls for this bullshit? Is there really a person who says oh my - I need to get that package back right away. I don't remember shipping anything, but I must have! and opens the attachments? Really???