Any and all notices, requests, demands and other communications provided for by this Agreement shall be in writing and shall be effective when delivered in person, consigned to a reputable national courier service or deposited in the United States mail, postage prepaid, registered or certified, and addressed to the Executive at his last known address on the books of the Company or, in the case of the Company, at its principal place of business, attention of the Chair of the Board, or to such other address as either party may specify by notice to the other actually received.