(1) The notice of termination shall be served upon each grantee whose rights are being terminated, or the grantee's successor in title, by:
(i) Personal service;
(ii) First class mail sent or by reputable courier service delivered to an address which, after a reasonable investigation, is found to be the last known address of the grantee or successor in title; or
(iii) Means of electronic transmission to:
(A) An email address designated for service of notices of termination and/or legal process that is listed as such on the website of the grantee or successor in title in a location accessible to the public;
(B) An email address provided to the terminating party by the grantee or successor in title, provided that the grantee, successor in title, or an agent thereof who is duly authorized to accept service on behalf of the grantee or successor in title expressly consents in writing to accept service at the address provided within thirty days before such service is made; or
(C) An email address for the grantee or successor in title provided in accordance with instructions provided on the Office's website in a public directory that the Office in its discretion may establish and maintain.
(2) The service provision of 17 U.S.C. 203, 304(c), or 304(d), whichever applies, will be satisfied if, before the notice of termination is served, a reasonable investigation is made by the person or persons executing the notice as to the current ownership of the rights being terminated, and based on such investigation:
(i) If there is no reason to believe that such rights have been transferred by the grantee to a successor in title, the notice is served on the grantee; or
(ii) If there is reason to believe that such rights have been transferred by the grantee to a particular successor in title, the notice is served on such successor in title.
(3) For purposes of paragraph (d)(2) of this section, a reasonable investigation includes, but is not limited to, a search of the records in the Copyright Office; in the case of a musical composition with respect to which performing rights are licensed by a performing rights society, a reasonable investigation also includes a report from that performing rights society identifying the person or persons claiming current ownership of the rights being terminated.
(4) Compliance with the provisions of paragraphs (d)(2) and (d)(3) of this section will satisfy the service requirements of 17 U.S.C. 203, 304(c), or 304(d), whichever applies. However, as long as the statutory requirements have been met, the failure to comply with the regulatory provisions of paragraph (d)(2) or (d)(3) of this section will not affect the validity of the service.