Claim: You can effectively establish U.S. copyright protection of your work by mailing a copy of it to yourself, then retaining the sealed, postmarked envelope as proof of the date of your authorship.
Status:Not in the U.S., but it might be of some assistance in Britain.
Copyright is the exclusive right to copy a creative work or allow someone else to do so. It includes the sole right to publish, produce or reproduce, to perform in public, to communicate a work to the public by telecommunication, to translate a work, and in some cases, to rent the work.
You establish your copyright the moment your work is created and fixed in a tangible form. While you need not register your works with the United States Copyright Office to establish ownership of your intellectual property, you will have to register such items if you wish to bring a lawsuit for infringement of a U.S. work. (The fees for such service are laid out on this page.)
As to why to register your works if they are already under copyright from the moment of creation, the United States Copyright Office says:
Registration is recommended for a number of reasons. Many choose to register their works because they wish to have the facts of their copyright on the public record and have a certificate of registration. Registered works may be eligible for statutory damages and attorney's fees in successful litigation. Finally, if registration occurs within 5 years of publication, it is considered prima facie evidence in a court of law.
one's works to oneself and keeping the unopened, postmarked envelope as proof of right of ownership to them (a practice known as the "poor man's copyright") has no substantive legal effect in the U.S. We've yet to locate a case of its use where an author's copyright was established and successfully defended in a court of law by this method. At best, such mailings might serve to establish how long the author has been asserting ownership of the work, but since the postmarked-and-sealed envelope "proof" could be so easily circumvented, it is doubtful courts of law would regard such evidence as reliable.
Ive heard about a "poor mans copyright." What is it?
The practice of sending a copy of your own work to yourself is sometimes called a "poor mans copyright." There is no provision in the copyright law regarding any such type of protection, and it is not a substitute for registration.
However, the U.K. Intellectual Property Office has this to say on the subject:
How do I register my copyright?
A creator could send himself or herself a copy by special delivery post (which gives a clear date stamp on the envelope), leaving the envelope unopened on its return (ensuring you also know what is inside each envelope in case you do this more than once). Alternatively you could lodge your work with a bank or solicitor. It is important to note, that this does not prove that a work is original or created by you. But it may be useful to be able to show the court that the work was in your possession at a particular date.
Careful readers will have noted the "may be useful" in the above entry.
Brad Templeton's page about copyright myths addresses eleven other misapprehensions about copyrights. (Yes, his page is titled "10 Big Myths About Copyright Explained" but there are eleven items listed on it.) Also check out his "Brief Intro" to copyright to further expand your knowledge of the topic. (Trust me; it's painless.)
Barbara "the write stuff" Mikkelson
United States Copyright Office
Canadian Intellectual Property Office
Where Did Copyright Come From? (Copyright Website)