Mrs. Honest, everything AustinMom said is both true and good advice.
I just want to add that some of the scammers are using the names of legitimate mystery shopping companies. Legitimate mystery shopping companies never, ever send unregistered mystery shoppers unsolicited checks in the mail. If you deposit this check to your account, in the hopes that it is real, I assure you, Mrs. Honest, you will be in a pile of hurt. Please don't do it!
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I intend to live forever. So far, so good.