The IP address of smtp.ntlworld.com is black listed by APEWS.org - I found that by putting the look-up IP address of smtp.ntlworld.com into
www.dnsstuff.com Spam Database Lookup.
If you aren't angry enough by having the plug pulled on your main form of communication, APEWS.org won't deal with end users to white list smtp.ntlworld.com and instruct you to go via your ISP (NTL/Virgin Media in our case who don't think there's anything wrong!! FFS)
Quite why this APEWS group of people think we need yet another spam black list is beyond me as they are just creating new Spam problems for legitimate businesses/individuals rather than solving them.
My next move is to locate a reputable email provider who is not black listed anywhere and operates in a manner to prevent black listing and has a feasable plan in place should they or any of their customers get black listed.
Hope this helps others who are unfairly suffering Spam black listings.