Qn: How to restrict in/out emails within a domain name/internal organisation only?
I have searched high and low for a solution to my problem but couldn't not find any. Really need help on this one.
I have a server that runs RedHat Linux 9.0. For one of the domain names, I wish to restrict email communications within that domain name only. That is, email@example.com could only send/receive to/from firstname.lastname@example.org and vice-versa. If you like, I am trying to implement a closed email system for communication within an internal organisation only.
Does anyone know how to achieve this?
Many thanks in advance.