Vt. Stat. Ann. tit. 32, § 3203

If the Commissioner finds that any taxpayer has failed to discharge in full the amount of any tax liability incurred under this title or has claimed a refund in error or that a penalty or interest should be assessed under this title, the Commissioner shall notify the taxpayer of the deficiency or denial of refund or assess the penalty or interest, as the case may be, by mail. The mailing of the notice shall be presumptive evidence of its receipt by the person to whom it is addressed. Any period of time that is determined under this chapter by the giving of notice shall commence to run from the date of mailing of the notice.