Getting emails to separate on home network

[Esther]

We have two user IDs on a home network using Videotron
cable internet. When we used Outlook Express, we were
able to split emails to each workstation by using the Do
not download from server command for the other persons
email address on each workstation. Now we are using
Outlook, and there is no such command, and I cannot seem
to enter a new command under Perform Custom Action...
How can I do this...