Oregon Revised Statutes Revenue and Taxation § 311.545

(1) As soon as practicable after taxes become delinquent each year, the tax collector shall send to each person, firm or corporation shown on the tax roll as owning real property on which the taxes due and charged have not been paid, a written notice, stating:

(2) The tax collector shall send the notice, in each instance, by letter mail to the last-known address of the person, firm or corporation shown on the tax roll, or otherwise reported to the tax collector, as owing the delinquent taxes.

(3) This section does not apply where the amount of the taxes delinquent against any particular parcel of real property is less than $1.