Open Ports on Windows 2000 Server

I have a Windows 2000 Server that runs Lotus Notes for the entire agency. We are going to web mail and the adminstrators have scanned my server for possible open ports before opening us up for web mail. They say they have found port 2473 to be open and they want it closed. We have traced the port to Aker which is supposedly some security company but either way if this is something illegitimate or not is there a way to disable this port? Or can someone tell me exactly what the port is and whether every server has this or is it something I can get rid of. Please give exact details on shutting the port down through windows. Thanks.