as to why you would want to set up a POP3 mailserver for just 2 computers.
A true mailserver must run 24 hours a day, 365 days a year - otherwise senders will get their mail bounced.
Why don't you just run your server normally, and install Microsoft Outlook on it? Then you can configure Outlook to go to your domain host's POP3 server at regular intervals, collect your mail and - using rules that you set up - distribute it to mailboxes on the 2 computers via the network.
It works very well, and you don't need to run a POP3 mailserver connected 24/7 to the Internet.