So I migrated from Exchange 2007 to Exchange 2013, and everything went well. I shut off the 07 server once everything was done to be sure there were no connections to the old server and test new server functionality on its own.
I left the old server off for quite awhile, about 3 months.
Today I booted it up to remove Exchange 07 and demote it from being a DC, etc.. and am getting all sorts of Active Directory errors - I think due to the tombstone time frame.
I need some help working through this to be sure AD stays in good shape, and safely decommission the old server. Anyone feel up to this?