A Times columnist looks at the question of if you can be sure that an e-mail you send gets received. Turns out dropped messages are possible, but that a company called ReadNotify is attempting to make this a thing of the past. Along with receipt notification, the company will offer a “self destruct” feature which will prohibit copy/pasting and will delete itself after a specified time.

Some experts have questioned whether such technology is legal under American law, but Mr. Drake says “e-mail tracking is legal because e-mail is ‘owned’ by the author.”

Naturally, laws are open to interpretation, but I think this reading of copyright is in error. Yes, when you write an e-mail it becomes “fixed” and you own the exclusive right to do publish or distribute it (among other things).  But note this is different from owning the e-mail. Once it is sent (distributed) one would naturally expect that you lose control over the message. There may be a license and Digital Rights Management that can give you greater control, but these happen because of an agreement–not because you still own the artifact you somehow disseminated on the Internet.