If you were a Delta SkyMiles Credit Card holder solicited for this offer, you can enroll online by entering the RSVP code found printed inside your mailing at http://www.americanexpress.com/delta2x. Or you can enroll by phone, by calling 1-800-794-1308 and entering code 086450001.

You’ll earn double miles on eligible spending posted to your account between April 15 and June 15, 2007. You must register for this promotion by June 15, 2007. See full terms and conditions on Amex’s site.