I'm finally getting around to getting rid of my 2010 after moving everything to 2016. The error is "This server is responsible for generating an offline address book. Removal is not permitted" It seems since I have multiple GALs, Address lists, Address book policies and OABs that its a challenge. I thought I could just delete them all and re-create on the new server but it won't let me delete. Each one says it's being used by the other, this and that, etc. It's a vicious circle. I still need all the address list and OABs for multi-tenant seperation. What do I need to do?