20 C.F.R. § 655.453
If an electronically filed TLC is denied, the CO will send the Final Determination notice to the employer and a copy, if applicable, to the employer's agent or attorney using an electronic method(s) designated by the OFLC Administrator. For employers permitted to file by mail as set forth in § 655.420(c), the CO will send the Final Determination notice by first class mail. The Final Determination notice will: