sending data as a fax data

I have a server computer and 5 other client computers. I dial each computer using my VB application to send and receive files/data. It works fine with 3 of the client computer and other 2 , i am not able to get it connected. This two computer are connected to a fax line . So when ever i try to dial this two computer from server computer, the exchange detect it as not a fax data and drops the line. I Want to bypass this problem. Is there a way

Are there any webMethods software products involved in this arrangement? Perhaps a general MicroSoft forum would be more appropriate for this question.