"The narrow issue before us is whether the seizure of a computer, used to operate an electronic bulletin board system, and containing private electronic mail which had been sent to (stored on) the bulletin board, but not read (retrieved) by the intended recipients, constitutes an unlawful intercept under the Federal Wiretap Act, 18 U.S.C. s 2510, et seq., as amended by Title I of the Electronic Communications Privacy Act of 1986, Pub.L. No. 99-508, Title I, 100 Stat. 1848 (1986). We hold that it is not, and therefore AFFIRM."