Out of curiosity: is posting internal company communications (referring to the e-mail here) on a public site like this legal? I'm not saying that it isn't; I genuinely don't know.
If the company involved has been wound up (rather than bought out) I'd guess it would be fairly safe. Who would sue, after all? I am not a lawyer. Or since this is UK, "I am not a solicitor" :)
It's only illegal if someone prosecutes. (See American Government)
It's unlikely a defunct company, run by a convicted guy, employing a person that didn't sign an employment contract (and by extension, a Non Disclosure Agreement) would pay attention to this, much less go after him.