Forum Discussion
Decomission of an old Exchange 2013 server
Hello everyone. I have a messy situation here. We contracted a small IT company to help us migrate from Ex2007 to Ex2019. I trusted them because they said they'd had experience upgrading Exchange. Fi...
If the EX2007 box was not removed properly from the Exchange organisation, then you would not have been able to install Exchange 2019. There may be some non-Exchange related objects left behind (ie DNS records, computer objects etc), but nothing related to the Exchange organisation itself. Regarding the OAB, you need to set the mailbox databases on all servers to use the OAB from the new server. To Decomm the EX2013 server, make sure that all mailboxes have been moved to the EX2019 server, delete the mailbox DB's, then run setup.exe /mode:Uninstall. This is a good rundown on what to do: https://techcommunity.microsoft.com/t5/exchange-team-blog/decommissioning-exchange-server-2013/ba-p/3613793