You may have noticed an unusual rise in the amount of SPAM getting through to select users on your domain. We have isolated dozens of domains against which large scale SPAM attacks have been raised, typically from trusted (reputable) mail infrastructure.
We have been isolating recent outbreak of SPAM that is originating from sources that are typically trusted and managed by larger providers. We have designed new rules, tested them against known sites and our own production domains and we can confirm that we expect the performance as of 2 AM EST to improve significantly. As usual, if you continue to see unusual SPAM levels please use the Outlook 2007 addin and report anything that gets through as the email@example.com alias will be discontinued shortly.