By default it isn't enabled, but as most spoofing sites will try to redirect you, I've had it enabled for a long time - but it seems that more than half the sites I try to go to these days are redirecting. So it has become a pain clicking anything in Gmail as I have to mouse over and allow the redirect by clicking in the top r.h. corner. (As I do a LOT of research, often 50 clicks from my emails every morning, this is tendonitis territory, not laziness! :-) ) So - how useful is this option? Especially when not even a default?