The snag is that they aren't going to give their users any control over it until January.
At the moment about 99% of the mail I'm getting there is spam, so it's definitely something that needs doing, but it sounds like there's a real possibility genuine mail will be blocked at first.
My other ISP, CIX, already has spam trapping which I don't 100% trust.
Accordingly I'd strongly advise anyone who has me in their address book to use my gmail address instead of NTLWorld for the time being. I strongly doubt that anyone needs to send me anything so confidential that you will be worried about the (minor) security concerns re. gmail. Just a reminder that it's
myfirstname dot mylastname at gmail dot com - I'm sure that if you can remember my name you can fill in the blanks!