Oregon Revised Statutes Revenue and Taxation § 305.820

(a) Transmitted through the United States mail or by private express carrier, shall be deemed filed or received on the date shown by the cancellation mark or other record of transmittal, or on the date it was mailed or deposited if proof satisfactory to the addressee establishes that the actual mailing or deposit occurred on an earlier date.

(b) Filed electronically pursuant to a rule of the department adopted under ORS 306.265 and 309.104 that authorizes the electronic filing and that meets the specifications and requirements of the rule, shall be deemed to be filed and received on the date actually received by the addressee, or on the date stated on the electronic acknowledgment of receipt that is sent by the addressee.

(c) Lost in transmission through the United States mail or private express carrier, shall be deemed filed and received on the date it was mailed or deposited for transmittal if the sender:

(a) “Private express carrier” means a carrier described under ORS 293.660.

(b) “Writing or remittance” includes, but is not limited to, “report,” “tax return,” “claim for credit,” “claim for refund,” “statement,” “notice of appeal,” “petition for review,” “notice of election,” “documentary proof,” a claim for exemption, a claim for deferral, a return of property, a claim for cancellation of an assessment, an application for a special assessment, and remittances.