I have a SBS 2003 domain e.g: “abc.com”. i added in one more email domain “def.com” . The issue is the abc.com domain and users all moved to new office, the def users still use the old server.
abc.com has their own server and public ip.
So when they create new users in abc.com, my def.com can’t send . No recipient errors , but the others can send. how can i solve it, i don’t want to reinstall a new domain def.com on the old server. what will be the best way to minimize user interruption?