15. Any notice or other communication regarding the contents of this Agreement to be given hereunder by each party shall be in writing and shall be delivered personally, or sent by courier (charges paid), registered or certified mail (return receipt requested, postage prepaid), or by email. Any such notice shall be deemed given (I) when personally delivered, (II) fifteen (15) business days after mailing by registered or certified mail, (III) seven (7) business days after mailing by courier or (IV) when transmitted by email with an answerback confirmation of receipt, unless otherwise changed by notice delivered in the manner provided above, to the addresses of each party as indicated at the end of this Agreement.