I recently found the solution to my adding a "disclaimer" to all outgoing emails - took me longer than I expected because it isn't a disclaimer as such so it took a few attempts to get the search phrase I needed!
The only bit that doesn't work quite as expected is when someone sends out an HTML email. It doesn't bother me as such (policy dictates plain text, as it should be) but one or two people have discovered Outlook stationary and I'm trying to figure out how to not have it lump a obtrusive line of black Times New Roman at the end of the grey-coloured email.
I've seen references to people creating separate plain-text and HTML disclaimers but haven't seen (or missed) mention of it in the wiki entry or forums.
Any pointers welcome!
PS - another EU legislation sufferer here, just voted on bugzilla for this to be a 'proper' feature!