Here's a copy of a reply that I've made to a post from someone else:
"There are a number of reports identical to this appearing in these forums. It's starting to sound like VM have made a DNS change on their side that's gone awry. If you stick with VM DNS, as I expect the general VM customer population do, there's nothing you can do to fix this. You could however reconfigure your computers, phones etc to point to some other DNS service if this is an urgent problem."