We've recently taken on anew clients with the purpose of performing a Hybrid migration to office 365, which requires Exchange 2007 to be on SP3. Their current environment is Windows server 2003 R2 running Exchange 2007 SP1. When I run the SP3 setup I get the warning:
"Cannot find Recipient Update Service responsible for the domain"
In digging further it appears that they once had an Exchange 2003 server in their environment that was removed years ago however it seems to still be tied to the environment in someway. Running Get-Exchange Server returns the old server, albeit with no roles installed, along with the new.
Per this similar post I have used ADSI Edit to look for Configuration\Services\Microsoft Exchange\<Organization Name>\Address Lists Container\Recipient Update Services however this path does not exist in the environment.
https://social.technet.microsoft.com/Forums/en-US/c8d16877-56d9-4f4b-b0e1-c427ea96a901/recipient-update-service-error-when-installing-exchange-2007-sp2?forum=exchangesvrdeploylegacy
It seems as though this error is related to the absence of an RUS which Exchange 2007 does not have nor need per my understanding. Do I need to do anything with this warning prior to installing SP3 (there are no resources on the old and long removed Exchange 2003 server) or can I safely ignore this warning and proceed with the SP3 install and ultimately my hybrid migration. We will very soon be decommissioning the Exchange 2007 server as well.