An employer's form 43, contesting a claim before the claimant filed his form 30C, alerted the claimant to the specific substantive ground on which the employer contested compensability and satisfied the requirements of C.G.S. §31-294c(b). On Dec. 4, 2007, the employer, Boehringer Ingelheim Corporation, sent by certified mail a form 43 to contest a claim for workers' compensation benefits by Thomas Lamar. Lamar never claimed the mailing. The form listed the date of injury as Sept. 6, 2007, the body part injured as lymph nodes, and the nature of the injury as sarcoidosis. The corporation indicated the reason for the contest was that Lamar "did not suffer an injury which arose out of or in the course of his employment." On Dec. 10, 2007, Lamar filed a form 30 C indicating a repetitive trauma injury with the date of injury as Jan. 1, 2005 through the present. He listed the body parts injured as "lungs, respiratory complaints." On Feb. 6, 2008, the corporation filed a second form 43. The commissioner denied Lamar's motion to preclude the employer from contesting benefits. The board affirmed the decision. Lamar appealed claiming, first, that the defendant's initial form 43 was invalid because it was not served in accordance with C.G.S. §31-321. The Appellate Court affirmed the board's decision.  Lamar unsuccessfully argued that because the corporation was aware that he had not received the notice, it was required to attempt personal service. However, the corporation properly used one of the three methods established in C.G.S. §31-321. The statute does not contemplate any further action if the intended notice recipient fails to claim it. Further, the notice met the specificity requirements for a valid notice to contest benefits. Lamar challenged the date of injury listed as incorrect. But, that date fell within the time period established by Lamar's form 30C. The form 43 satisfied the statutory requirements of C.G.S. §31-294c(b). The corporation indisputably investigated the claim promptly, as its form 43 was filed before Lamar's form 30C. The form 43 alerted Lamar to the specific substantive ground on which the corporation contested compensability and was found sufficient.