Answered By: Michael Pujals Last Updated: Dec 06, 2019 Views: 2
The Copyright Office refers to this as Poor Man's Copyright. Straight from the Copyright Office:
The practice of sending a copy of your own work to yourself is sometimes called a “poor man’s copyright.” There is no provision in the copyright law regarding any such type of protection, and it is not a substitute for registration.
With copyright law, you own copyright as soon as you put your original work into a fixed format. You can take the step to register copyright with the Copyright Office if you want to bring copyright lawsuit for infringement.