Communication Strategy

We are trying to set up a batch job in which all invoices created during the day will be faxed at night. If there is no fax # in the master then the invoice would print. We would use a communication strategy for this correct? If the fax was unsuccessful, is there a way to make the invoice also print?

A condition technique was set up for combo of sales org & customer #, then in the condition record we put each customer & the partner that the invoice should be faxed to. I am very new to SD, am I on the right track?

Thank you in advance for any assistance!