"It is not possible to guarantee returns and therefore no sane fund manager would ever do so. Most investment managers whether running regulated or unregulated schemes will publish health warnings (e.g. past performance is no guarantee of future performance, shares can go down as well as up etc etc) but will also highlight why they think they will be able to create value for the investor.
The FSA has extensive rules on financial promotions and the degree of information and inducement you can put into your marketing depends on what level of authorization and regulation you have as the investment manager. This also dictates who you can market to."
A subsequent email stated: 'You do realise that printing this without permission is 100% against the law.'
Frankly I think it is highly unlikely that the law is at all clear cut on this. This might be of interest. I suspect in law much would depend upon the content of the email and whether the recipient had indicated that they would abide by the confidentiality signature.