All notices provided for in this section 3-4-8 are properly served when delivered to the holder of the license, the person in charge of any part of the business operated under such license, or other agent of the license holder, or when sent by registered or certified mail, return receipt requested, to the last known address of the holder of the license. In either case, the date of receipt shall be deemed the date of service. A copy of the notice, with sworn proof of service, shall be filed in the office of the city clerk and maintained as part of the licensee's file. (Ord. 04-45-0, 12-9-2004)