Apple Logic Pro /LogicExpress Discussion

I know this has nothing to do with music but here I go. 
In my studio I am, of course, online but more or less only to be able to get updates or other music related stuff. Now and then I have to receive a little email on that computer ie yesterday when  needed to register a plugin. 
Now the problem comes, my wife and son also has email coming from the same account but under their own email addresses. 
In Tiger all I can figure out to do is to automatically send them back on the server again which means that the messages accumulate and is doubled many times during a day so my sons 10 messages becomes 200 if I have picked up my mail 4-5 times that day.
In (Windows) Outlook Express there is a way to get the program to leave the messages on the server that includes certain words in the "to" box (in my situation my familys email addresses) which is perfect for distributing emails in a household like ours.
I magine that this is a pretty normal situation so I would like to believe that there is a way to set up the Mac mail program to act like Outlook Express but how????

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