Req: HP950 Multi-Function Printer - Fax Problem

This may not be the right group - but I'll try anyway since I can't
find another nor can I find a way to email HP.

My HP 950 always acts the same when I try to send a fax.
No matter what number I am calling it is always rejected as 'busy' at
least once, and sometimes two=three times, before my fax is finally
sent. I have checked and the recipient's number is not busy.
So I know something must be set wrong here.

Can anyone help? Either with a suggestion or with the proper
newsgroup, or a HP email address for Customer Support?

Thanks