(Full disclosure, this is a double post since I wasn't sure if this was considered a Newbie question. I can close the other thread if this belongs here)
I'm an average Linux user and didn't orginally set up SendMail but I have run into this issue. I have emails on RackSpace with the same address as emails on this Local Linux box. So both are "@company.com"
So when someone sends a message to email@example.com
(lets say they are on rackspace) and another to firstname.lastname@example.org
(they are on the SendMail Linux box) there are issues. I know the solution is split domain routing, and I've done that on RackSpace since there is a tool for it but I don't know how to do it on the Linux box. The users on RS can't email users on the local box.