Common email account

I have multiple users proxing to common email account called Message Center. They don’t use it to send mail just to view the mail inside it. I have one user who can’t connect to it. When I try to proxy to it logged in as her it says that I don’t have the rights. I need to find out what program I need to use to give her the rights she needs. She’s is in the same groups as the other users. I have looked every where in nwadmin. I didn’t setup this network so that is why I don’t already know. They are running Novell 5.2 and Groupwise 5.5