Black-holing Username Mailboxes

[#1]

Some time last year, we were offered a free domain to combat the excessive amount of spam. In the FAQ at the time it was said PlusNet were looking at the possibiliy of black-holing the original 'xxx@username.plus.com' email addresses so that the address 'xxx@new-domain.co.uk' could be used exclusively. The FAQ stated and still states this facility should be available in a few weeks.
Was this facility ever implimented and what is the position today?

[#2]

That functionality is available but it's only support staff that can turn this on/off. If you want I can go turn the @username.plus.com address off now for you?

[#3]

Many thanks for your quick reply.
I'll leave it for the moment and see how things go. I have just received 2 phishing emails to the username but most spam is now being blocked.
The phishing emails were 'Abbey National' and 'New Egg'. These were deleted.
If the @username.plus.com is turned off, will mail to that address be returned to the sender?

[#4]

If you are having problems with inappropriate emails being sent to "username@username.plus.com" then you can set up an alternative default address of "anothername@username.plus.com" using the "Manage my Mail" facility on the Members' Portal. 
Once the new name is set up you can blackhole the old one (emails would NOT get returned to sender though) via the same mail management facility.  Alternatively you can allow the old address to continue to be used for a few days or weeks to check who is still using it before deciding to turn it off.  After the Spam email problems last summer I did this and have not had any spam mails since last August (which was the position I had been in for the previous ten years)
Good luck with whatever you decide to do  

[#5]

Thank you 'jazz' for your suggestion, I did try that originally but I guess I'm attached to my original 'mailname' and the plan is to use this with the 'new_domain' and eventually turn off the original 'username'
I get very little spam now but as I said I did just get the 2 phishing emails which got me thinking about turning off the original 'username' and I wasn't sure if this was possible.
The domain approach has the advantage you could take it with you if you changed ISP, not that I have any intention of doing this but things change sometimes.
I was hoping emails to a canceled email address would be returned to the sender and give them a taste of their own medicine.
However, thanks again for your comments.