Legitimate or not they don't seem particularly ethical. I wouldn't trust them with my email let alone the huge amount of personal information they want before they even mention there is a fee involved.

Fees which aren't in red, brackets, with a minus sign in front of it or even in a different column as well as being mixed in with various other figures which all have different meanings. Plus it's on a page that front and centre and in large bold letters are the words "...Nothing to Pay...".

In my opinion the whole thing stinks of tricking people who aren't paying attention or know enough into paying for a free service provided by the ATO. If that's the moral standard of a legitimate tax accountant then what kind of fucked up society are we living in?