The law regards each of these situations as distinct.
1. Interception of e-mail during transmission is prohibited by federal wiretap statute, 18 U.S.C. § 2510-2521 and also some state wiretap statutes. The federal statutes were amended in 1986 by Title I of the Electronic Communications Privacy Act (ECPA) to include e-mail.
2. Reading e-mail during storage on a computer system is prohibited by federal statute, 18 U.S.C. § 2701-2711, Title II of the Electronic Communications Privacy Act (ECPA), provided that the system is "providing an electronic communication service to the public." This means, among other things, that your e-mail messages are confidential when stored on a computer owned by an ISP that offers to any member of the public the ability to send e-mail and you pay for the account yourself. But there is no protection in 18 U.S.C. § 2702 for e-mail stored on a computer system operated by a corporation primarily for its own business communications. So, if you send e-mail to a company (e.g.,
jdoe@ibm.com) and the e-mail is stored on that company's computer, you have no privacy rights under this statute.
3. The recipient of e-mail is generally free to share the information in the e-mail with anyone.Reading e-mail that is stored on a computer is not an "interception" under 18 U.S.C. § 2510, et seq., because an interception must be contemporaneous with the transmission of the message between different locations. Steve Jackson Games v. U.S. Secret Service, 816 F.Supp. 432, 442 (W.D.Tex. 1993), aff'd, 36 F.3d 457, 460 (5thCir. 1994). This holding has been accepted in several subsequent cases, including Wesley College v. Pitts, 974 F.Supp. 375, 384-390 (D.Del. 1997); U.S. v. Moriarty, 962 F.Supp. 217, 221 (D.Mass. 1997); Bohach v. City of Reno, 932 F.Supp. 1232, 1235-36 (D.Nev. 1996).
One court noted that there is a loophole in Title II of the ECPA, where an unknown person can make a copy of e-mail and give it away, then other people who do not provide an electronic communication service can lawfully make a further distribution of copies of that private e-mail. Wesley College v. Pitts, 974 F.Supp. 375, 389 (D.Del. 1997).