Following the separation of companies i was asked to define two separate mail servers with the same domain name @ domain.com.
the companies should be cut off completely.
There is no sharing of information between companies and no sharing users.
MX record are set to different priority,
from what that I know,the two companies can still set up the exchange server to access each other mail account, the CEO or any user who is using the Competitor company.
The two companies do not want to change the domain so it was decided on this option.
How can I prevent the above problem and make an absolute disconnect between the companies with unchanged the Domain Name.
Any help is welcome