I just received an assessment notice claiming I hadn't paid the income tax on my 2011 Massachusetts returned I filed electronically.  Only trouble is, the notice was dated April 16, and the payment deadline was April 17. That's when I paid it, by electronic debit. Their website shows that the payment was posted.  Called the DOR, and was told, "That shouldn't have happened, I'll have to check into it?"  Can't believe this only happened to me.  Anyone else?