In actions brought under Code § 8.01-654, filed by an inmate confined to an insfitution, a paper is timely filed if deposited in the institution’s internal mail system on or before the last day for filing. Timely filing of a paper by an inmate confined to an institution may be established by (1) an official stamp of the institution showing that the paper was deposited in the internal mail system on or before the last day for filing, (2) an official postmark dated on or before the last day for filing, or (3) a notarized statement signed by an official of the institution showing that the paper was deposited in the internal mail system on or before the last day for filing.