First of all, and this bears repeating, the IRS is not going to notify you of any situation by e-mail. Ever. Nor will the IRS send you a text message. So if you get a text message that says, "OMG, Yur like all behind on yer taxes...hit us back asap", it's probably not the IRS
Unfortunately, the latest IRS scam is a little more subtle. If you know what to look for, you won't get taken.