Is it possible to set up mutiple user accounts in outlook and be able to view the inbox to email account that is not set as the default

What i would like to do is to be able to set up another email account via outlook 2003 or 2007. the reason for this is we would like one person to have access to this account but when that person is not in the office to have the same account on another users computer so they can use it. what settings would have to be set up for this to happen, right now we have a pop 3 servers where our emails are coming so i am guessing if say 2 users want to recieve that same email each user will have to leave a copy of the message on the server for example a day or two otherwise i am assuming that the first user to pop that email off the server will be the only user that recieves the email? Also i set up the 2nd email account up on my computer running outlook 07 and i am having problems recieving email through that account would that possibly be because the other user who has this account on their pc is not leaving a copy on the server?
thanks