What is the test for establishing that a letter correctly addressed and properly mailed was received in the ordinary course of mail?

Evidence Code, Sections 630 and 641 create the rebuttable presumption that a "letter correctly addressed and properly mailed" was "received[181 Cal.App.3d 22] in the ordinary course of mail" ( 641). This rebuttable presumption "require[s] the trier of fact to assume the existence of the presumed fact unless and until evidence is introduced which would support a finding of its nonexistence, in which case the trier of fact shall determine the existence or nonexistence of the presumed fact from the evidence and without regard to the presumption." (Evid.Code, 604.) However, nothing in section 604 "shall be construed to prevent the drawing of any inference that may be appropriate." (Ibid.; see Taylor v. State Bar (1974) 11 Cal.3d 424, 433, 113 Cal.Rptr. 478, 521 P.2d 470.)