The LCS 2005 users in home server cannot send IM messages to an user homed in the OCS 2007 server it is the problem. Presence state of OCS 2007 are unknown.
How it can be solved?
In case a user is SIP enabled, then that will imply that the presence should be unknown. If you add a user that either does not exist or the user is not SIP enabled, then the Presence status of the user will be unknown. Also, in case you try to send a message, you will receive an error message that tells you that "This message was not delivered to due to an error: More details (ID:1003)". What you will be required to do in that case is to verify that the user that you are trying to add either exists or is SIP enabled. Otherwise you will not be able to send the IM messages as you have just stated above.
-Thompson Locker
Â
