Notice shall be presumed to occur no later than five business days after transmission by certified United States mail.
§ 287.140, RSMo
RSMo 1939 § 3701, A.L. 1951 p. 613, A.L. 1957 p. 560, A.L. 1959 S.B. 167, A.L. 1965 pp. 397, 413, A.L. 1977 S.B. 49, S.B. 399, A.L. 1980 H.B. 1396, A.L. 1983 H.B. 243 & 260, A.L. 1988 H.B. 1277, A.L. 1990 S.B. 751, A.L. 1992 H.B. 975, A.L. 1993 S.B. 251, A.L. 1998 H.B. 1237, et al., A.L. 2005 S.B. 1 & A.130, A.L. 2013 S.B. 1
(1987) Employer is liable for medical expenses incurred by claimant even though claimant selected her own medical providers and employer was not notified of need for medical treatment until expenses had been incurred where claimant did not know she had suffered a compensable injury until after physician advised by letter that employment was suspected of causing medical condition. Sheehan v. Springfield Seed and Floral, 733 S.W.2d 795 (Mo. App.)