Important Changes to the .NET Messenger Service Microsoft Corporation is releasing Microsoft Live Communications Server 2005 with Public IM Connectivity (PIC) which enables instant messaging (IM) capabilities between the .NET Messenger service and corporate Instant Messaging systems. .NET Messenger users are now able to IM users of a connected IM system, in addition to the .NET Messenger users they IM with today.
As part of this service enhancement, you may have to change your sign-in address in order to continue using Messenger. Click the link to view more information about this issue.
How-to articles - Microsoft Office Live Communications Server 2005