Outlook Customs Forms

I have created a new form for a client. They are on NT 4 with all the services releases and Exchange Server. I created an Organizational Forms Library folder and placed the new form into that folder. Inter- office everyone can see the form. But when I send the form over the internet to a person they are not able to see the form nor the data entered into the fields. Any thoughts what I may be doing wrong or what I can do address the problem?