All communications, notices, consents, waivers, and other communications under this Agreement, the MSR Purchase Agreement and the Sale Supplements must be in writing and be given in person or by means of facsimile or email (with request for assurance of receipt in a manner typical with respect to communications of that type), by overnight courier or by mail, and shall become effective: (a) on delivery if given in person; (b) on the date of transmission if sent by facsimile or email; (c) one (1) Business Day after delivery to the overnight service; or (d) four (4) Business Days after being mailed, with proper postage and documentation, for first-class registered or certified mail, prepaid.