In addition to Mike-In-MD's correct answer, read this ... carefully!
http://www.fdic.gov/consumers/consumer/news/cnwin0607/scams.html
Extract:
"In these cases, the depositor most likely will be held responsible for the entire amount of the fraudulent check."
Instead of cashing the check, or sending it back, take it and the envelope in which it came to the post office. They will use it as evidence and pursue the scammer.
I recieved a check for 3900 on Horizons bank and a letter from jobsolutions, with the phone # 1-647-894-6077 when I looked it up it was a real # except it belonged to a water company in ohio. Please be careful. this has happened to me before and when I tried to cash the check I almost got arrested which is why I checked into it.
I have already received 2 of these dumb checks..postmark,Canada...check from California/amount was 3900. on each one. First one I took to bank manager,HE SAID:SCAM so I tore it up,then came the second one,and I remembered the word SCAM, so tore it up and dumped it..it really feels good to throw all this money away!! Now heres a plan..open a new account in another bank..see how much time that gets ya.By the way I also get e mails from the FBI telling me that Nigeria is trying to send me 10,000 dollars,and I am under investigation for terrorists activities,they might have me on that one cause I definately terrorize any stray cats in my yard..I just love the internet,I can always count on a new surprise every day/TAKE CARE EVERYONE..LOL
I got this check because i responded to a job on craigslist as an adminstrative assistant. he said he would hire me and for me to send out gift to kids after i got the money. it was very odd. Of course i called the bank after googling it and it seemed the bank was real but she said do not cash it cuz the check was fake. So here it is in front of me and i sure as hell wished i knew how to get back at them. so sad!