Hey, if I write an email, I own the copyright, correct?
The encryption is a method I use to keep others from reading said copyrited work, correct?
This means that removing the encryption is in effect, circumventing a copywrite protection, and illegal under the DMCA.
No, you misunderstand what is going on here.
StartTLS is something that happens when your email client connects to the mail server with an insecure protocol on a non-ssl port, and then asks the server to switch to a secure connection. Its your clue that you are doing it wrong,
Connect on a secure port over ssl (usually 465) instead of 25. Set your client up right to use a secure port and they can't deny a secure connection. (Unless they don't support security at all, in which case run away from them like your hair is on fire).
WITHOUT doing it right, your email was never secure, never encrypted, so no DMCA violation.
They aren't denying you a secure connection, they are just putting the burden on you to do it properly instead of having their servers to the extra work of switching an insecure connection to a secure one, which usually entails a whole bunch of handshake-security dance.
Set your client up the right way on the right ports.