Windows Live Blocks MessageLabs Customers

Microsoft has apparently blocked all messages from MessageLabs' email servers destined for Windows Live accounts.

Customers of the MessageLabs spam filtering and e-mail security service have been unable to send to Windows Live accounts, such as Hotmail addresses, since Friday.

"We have been recently made aware that Windows Live has implemented a block on our IP address," reads an automatically generated email from MessageLabs in response to support requests. "We are in the midst of engaging their support teams to reach a resolution on this case."