Oxford Brookes University and other universities that connect to the internet via JANET is blocked from Hotmail. JANET is a shared academic network.

Microsoft is working to resolve the problem but Oxford Brookes has not heard anything back from it.

BT, Yahoo! and Comcast appeared to be blocking email from universities too and a random basis.

Both Microsoft and BT had not responded about this issue. The reason for the apparent block is currently unknown.

Source: The Register