Legal Question in Employment Law in Massachusetts

You should take your paperwork to an attorney to make sure it is legitimate. It is certainly possible for the MA DOR to work with other states in order to collect things like unpaid child support. If this is collection action on a judgment, you should have paperwork and notices of the court action. It is impossible to say whether this is legitimate without looking at the paperwork, but you have every right to be highly suspect. I wouldn't pay a dime until you have verified the validity of the underlying judgment/debt/obligation.