i'm working in my test lab system.
I have 2008 DC with Exchange 2007, 2010 and now 2013.
before installing the 2013 message delivery between 2007 and 2010 worked without issues.
however after installing 2013 message delivery between 2010 to 2007 stopped. 2013 to itself fails. 2007 to 2010 works but not to 2013.
i'm struggling to find all possible causes and solutions. I can't work out all of the 2013 changes to message tracking yet but the 2010 message tracking shows that the ip address of the servers are ipv6. as of yet I have not configured any ipv6 addresses so maybe this is part of the problem or not. i'm trying to deal with the message delivery issue and also look into *how to step-by-step* configure ipv6 too.
question 1: what do I need to look into the issue of the Exchange message delivery failures. then I will have to look into setup ipv6 properly.