I have difficult requirements in this installation.. I have domain.com hosted in US which is for x company world wide, on each country there is mail server, I will assume that the x, y and z are the countries.
I wanna the employees of x country to be able to send and receive the @domain.com from their server, (for sure the emails that sent by the staff only) at the same time we need the download also the emails that have been sent by gmail, hotmail, and yahoo etc.. from US Server.
The main SMTP must be the US server. and each country must receive from the local server (emails that are on the same domain.com) and from the US server (for the emails that are not on the domain).
how do I configure the mail server of each country in order to get the emails from the local SMTP and Global?