A holder of unclaimed property may establish its knowledge of the existence or whereabouts of the owner of that property by recording any owner-generated activity relating to that property. The mailing of a statement, confirmation, or other correspondence by a holder of unclaimed property to the last-known address of the owner of that property and the nonreturn of such mail to the holder is insufficient to establish that the holder has knowledge of the existence or whereabouts of the owner.
34 Tex. Admin. Code § 13.3