This from their status page about 60 seconds ago
" Network Issues
We are currently investigating what looks like a power outage in Tele House North which is affecting a number of services. We currently believe these services are:
Some mail Relays
The Phone System
These services are run across several servers and locations so not all customers will be affected however some customers will see slow down or loss of connectivity, please do not raise tickets on these issues as we will have them resolved as soon as possible.
All updates are available from our service status tool."