Apparently those stupid email footers mean absolutely nothing (according to The Economist):

Many disclaimers are, in effect, seeking to impose a contractual obligation unilaterally, and thus are probably unenforceable. This is clear in Europe, where a directive from the European Commission tells the courts to strike out any unreasonable contractual obligation on a consumer if he has not freely negotiated it. And a footer stating that nothing in the e-mail should be used to break the law would be of no protection to a lawyer or financial adviser sending a message that did suggest something illegal.