Your email footers are stupid and not enforceable.

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Have you ever gotten an email and at the bottom it said something like: This e-mail is property of .  It is intended only for the person or entity to which it is addressed and may contain information that is privileged, confidential, or otherwise protected from disclosure.  Distribution or copying of this e-mail or the information contained herein by anyone other than the intended recipient is prohibited.

I'm NOT a lawyer but my fucking god read some simple business law books.

You'll be pleased to note that aside from violating a company policy, which is a non-issue in most cases when it's sent to a person outside of said company this and almost every other variation on this footer type email is unenforceable. No binding agreement came from you reading the email, there was no meeting of the minds prior to you reaching the bottom of the page. In other words, it's a waste of bytes.

Now, if you are an employee of said company, and you got such an email, you could be terminated and be actioned upon for violating their policies. As a customer, if you pissed them off they could decide not to do business with you... but that is literally the ballgame.

Imagine your name is Joe and someone walks up to you and goes "HEY Bob! There's a great opportunity in X X and Y but don't tell anyone!" as far as I know (and I know a fucking lot) you are under no obligations to keep that to yourself. You can freedom of speech that thing all over the world.

Be more careful about who you talk to, make prior non-disclosure agreements with who you talk to. But a footer in the email? No. It just makes me mock you. A certain YouTube network, one SMALL marketing firm, and two job source websites all were the victims of said mockery.