(1) Orders of the Department of Revenue in property tax cases shall be served by mailing a copy by certified mail to each taxpayer directly affected, or to the attorney or authorized representative of the taxpayer, except that whenever the number of taxpayers whose property is affected by such order exceeds three, the department may, in its discretion, give notice of the order in either of the following ways:
(a) Mail to each taxpayer a notice of the order, which notice shall contain a general statement as to the effect of the order, the classes or types of property affected and a description of the general area affected, as provided by ORS 308.240; or
(b) Cause a notice of the order as described in paragraph (a) of this subsection to be published in some newspaper of general circulation in the county in which the property is located, in two consecutive weekly publications, the first publication to be made within 10 days of the date of the order. Publication shall be deemed complete five days after the last publication and shall be sufficient service of the order on each and every person whose property is affected. Any period of time within which such person may appeal from the order shall commence running on the day following the completion of publication.
(2) All other orders of the department shall be served by mailing a certified copy to the taxpayer, executor or other person or persons directly affected by the order, or to the attorney or authorized representative of the taxpayer, executor or other affected person.