Exchange Server 2007 and leap year day Feb 29 2008...
EDIT 4/3/2009: We wanted to update this blog post to say that this problem has been fixed in Exchange 2007 SP1 RU5. For more information, please see KB 949893.
We have been made aware that some of our Exchange 2007 customers have been experiencing the following issue today:
When trying to make certain configuration changes such as new-mailbox or enable-mailbox, certain set of our customers would receive the following error:
"The Exchange server address list service failed to respond. This could be because of an address list or email address policy configuration error."
Additionally, if you have attempted to set up new Exchange 2007 servers today, your setup might have failed because of the same error.
After investigation of this problem we have learned that this problem would occur only if you have started or restarted the Microsoft Exchange System Attendant service between 12:00AM UTC , Feb 29, 2008 and 12:00AM UTC, Mar 1, 2008. It is important to note that the times involved are UTC, not local server time.
If you are impacted by this, all that you have to do is restart the Microsoft Exchange System Attendant service after the midnight UTC, March 1, 2008. Restart of the System Attendant will not disrupt your Information Store service.
We are working on a permanent fix for this and will update this blog post when it becomes available.
You Had Me at EHLO.