It seems three would be possible, but really it is the same thing as 2 since you would probably still want to include a random url parameter so you could verify they actually got the email and didn't know to go to the specialized login page directly. 
Mmm. Bit beyond me that :)
I can see how two can be done as they would have to login to do it wouldn't they? and the reason for all this is that they can't login.
Could I just ask you to explain the random url parameter bit?
Many thanks for taking the time with this. It's appreciated.


